Region locked:

Border Pioneer: LATAM, RU/CIS, SEA. TR receive region locked keys; everyone else: https://steamdb.info/sub/1152610/ which is not redeemable in the above regions (confirmed).
Stray Path: LATAM, RU/CIS, SEA. TR receive region locked keys; everyone else: https://steamdb.info/sub/1152606/ which is not redeemable in the above regions (confirmed).
PlateUp: everyone probably receives https://steamdb.info/sub/1300388/ which is redeemable everywhere apart from CN, HK, TW, MO

Some subs

There are no region locks.

Not sold in China (maybe other countries too?).

https://www.fanatical.com/en/pick-and-mix/build-your-own-capcom-all-stars-bundle
Not sure if this is too tempting to anyone, but a lot of the items are 'low stock' apparently

This is part of a New bundlefest. I'll need to create a thread for the fest as well.

Instruments of Destruction: LATAM, RU/CIS, SEA, perhaps ME too receive region locked keys. According to Fanatical API, EU should receive a region locked key, but it's more probable that EU / NA / Africa / Oceania receive region-free keys (or, worst case, a "Tier 1" countries sub). Since none of subs aren't indexed on SteamDB, it's hard to say without a confirmation from someone who bought the bundle.

Region locked:
Besiege: RU/CIS, LATAM, SEA receive region locked keys; everyone else: probably a "Tier 1" countries sub
Human Fall Flat: customers from CN do not receive the game; everyone else probably receives https://steamdb.info/sub/803062/ which cannot be redeemed in CN.

I don't really know what The Capcom Retro Revival Pack contains. Since the lineup on the bundle page is confusing and misleading, only someone who buys the bundle can confirm the actual contents.
It could be delivered as 3 keys: Capcom Arcade Stadium Complete Pack, Ghosts 'n Goblins Resurrection, Dungeons & Dragons: Chronicles of Mystara.
Or, it could be delivered as 4 keys: Capcom Arcade Stadium Packs 1, 2, and 3, Capcom Arcade 2nd Stadium Bundle, Ghosts 'n Goblins Resurrection, Dungeons & Dragons: Chronicles of Mystara.
Strider can either be the STRIDER app (this, one extra key added to the above items), but it's more probable that it's the Strider DLC included in Capcom Arcade Stadium.

The bundle isn't available in China.
Strider: Everyone receives {sub/38650} which cannot be redeemed in Japan. According to the gift link notification, customers from RU do not get a key.
Capcom Arcade Stadium Complete Pack: Everyone receives a WW-redeemable key, aside from customers from RU who do not get a key.

Possible region locks for Build Your Own Special Editions Bundle:
Wolfenstein: The Two Pack
The Evil Within Bundle
Wolfenstein: Youngblood - Deluxe Edition
Prey - Deluxe Edition

Region locks:
Deathloop - Deluxe Edition: despite Fanatical API mentioning region locks for all countries, everyone probably receives a WW-redeemable key https://steamdb.info/sub/434696/
Star Wars™: Episode I: Jedi Power Battles™: LATAM, RU/CIS, SEA, ME (incl. TR), EU receive region locked keys. Everyone else: probably a key that can be redeemed everywhere apart from Russia (either sub/879432 or sub/879431)
Badlands Crew: LATAM, RU/CIS, SEA should receive region locked keys. According to Fanatical API, EU also receive a region locked key. These subs aren't indexed on SteamDB, thus it's difficult to say if this info is correct.
Planet Zoo: LATAM, RU/CIS, SEA, maybe TR should receive region locked keys. According to Fanatical API, everyone else should receive a "Tier 1 countries" sub (does not exist on SteamDB)

https://www.steamgifts.com/discussion/UNf9t/humble-bundle-humbling-soulslike-bundle

https://www.humblebundle.com/games/humbling-soulslike-bundle

TemTem and Farewell North must be redeemed before March 8th, 2026.

All other titles need be redeemed before Oct 8th, 2026.

Cassette Beasts:

• RU/CIS: probably {sub/863938}
• CN: probably {sub/863939}
• ME + TR: probably {sub/863940}
• LATAM: probably {sub/863941}
• SEA: probably {sub/863942}
• Everyone else receives a "Tier 1" countries sub that is redeemable everywhere apart from the above regions. (confirmed)

Moonstone Island:

• RU/CIS: probably {sub/934238}
• CN: probably {sub/934239}
• ME + TR: probably {sub/934240}
• LATAM: probably {sub/934241}
• SEA: probably {sub/934242}
• Everyone else receives a "Tier 1" countries sub that is redeemable everywhere apart from the above regions. (confirmed)

🔑 Full list of subs

Vambrace Bundle: not available as a choice in RU/CIS. Everyone else should receive worldwide-redeemable keys.
Legendary Hoplite:ME+ZA, LATAM, RU/CIS receive region locked keys (these are not indexed on SteamDB yet). Everyone else probably receives worldwide-redeemable keys.
Rock of Ages 3: Make & Break: customers from JP likely do not have this as a choice. Everyone else probably receives {sub/371787} which can be redeemed everywhere but not in JP.
These Doomed Isles: SEA, RU.CIS, India, Turkey, LATAM receive region locked keys. Everyone else probably receives a "Tier 1" countries sub

Region locked:
Pine Hearts: RU/CIS, SEA, LATAM receive region locked keys. According to Fanatical API, EU should also receive region-locked keys, but it's hard to say because none of these subs are indexed on SteamDB. It's more likely that EU / NA / Africa / Oceania receive a "Tier 1" countries sub. Confirmation needed.

💦 IMPORTANT: Some items are for Epic Games Store, not Steam!!!

There are no region locks, all keys can be redeemed worldwide.

Forager and State of Decay 2: Juggernaut Edition must be redeemed before April 15th, 2026.
All other titles must be redeemed before Oct 15th, 2026

Chernobylite Premium Edition is delivered as one key https://steamdb.info/sub/337010/.

Region locked:
Conan Exiles

• RU/CIS + TR: probably https://steamdb.info/sub/267435/
• ME + ZA: probably a region-locked key, not indexed yet
• LATAM: probably https://steamdb.info/sub/311225/
• SEA: probably a region-locked key, not indexed yet
• CN+TW+HK+MO: probably https://steamdb.info/sub/435275/
• Everyone else: https://steamdb.info/sub/268409/ (confirmed)

Forager:

• RU/CIS: probably https://steamdb.info/sub/437439/
• CN: probably https://steamdb.info/sub/437440/
• small LATAM: probably https://steamdb.info/sub/437441/
• small SEA: probably https://steamdb.info/sub/437442/
• TR: probably a region-locked key, not indexed yet
• Everyone else: https://steamdb.info/sub/220956/ (confirmed)

Back in stock without GigaBash and Lonely Mountains: Downhill but $1 cheaper.

In comparison to the original bundle:

• Ten Dates was added
• Case Files: Behind Closed Doors is not included any more

Note: The Bunker wasn't there for me when the bundle launched, but it appears now after some hours. It has been re-added to the bundle in the meantime.

Some region lock info can be found here.

Region locked:

Brewmaster: Beer Brewing Simulator: RU/CIS, CN, smallSEA, LATAM, maybe also IN+TR receive region locked keys; everyone else probably receives a "Tier 1" countries sub that cannot be redeemed in the above regions.
ROUNDS: RU/CIS, SEA, LATAM, maybe ME + ZA + TR too receive region locked keys; everyone else probably receives a WW-redeemable key.
4-Player Mayhem Bundle: customers from China do not have this item as a choice; everyone else probably receives PRC-restricted keys for the games included in this pack.
KINGDOM of the DEAD: RU/CIS, SEA, LATAM do not have this game as a choice; everyone else probably receives a "Tier 1" countries sub that cannot be redeemed in the above regions.

Region locked:
Warhammer: Vermintide 2
Warhammer 40,000: Space Marine - Anniversary Edition
maybe Warhammer 40,000: Battlesectot too (unknown for now)

SEA subs:
https://steamdb.info/sub/251875, Warhammer: Vermintide 2 (ASIA)
https://steamdb.info/sub/347428, Warhammer 40,000: Inquisitor - Prophecy
https://steamdb.info/sub/63026, Warhammer: End Times - Vermintide
https://steamdb.info/sub/435008, Warhammer 40,000: Dakka Squadron - Flyboyz Edition
https://steamdb.info/sub/191835, Warhammer 40,000: Mechanicus Standard Edition
https://steamdb.info/sub/232060, Warhammer: Chaosbane
https://steamdb.info/sub/640535, Warhammer 40,000: Space Marine - Anniversary Edition -Retail - [Digital] (CTHM)
https://steamdb.info/sub/126432, Warhammer 40,000: Inquisitor - Martyr
?, Warhammer 40,000: Battlesector
?, Warhammer 40,000: Battlesector - Blood Angels Elites Pack
?, Warhammer 40,000: Battlesector - Tyranid Elites Pack
https://steamdb.info/sub/462496, Shootas, Blood & Teef

DeathSprint 66: RU/CIS, SEA, LATAM receive region locked keys. Everyone else probably receives a "Tier 1" countries sub, not indexed yet.
Bloodstained: Ritual of the Night: RU/CIS, SEA, LATAM do not have this game as a choice )although locked subs exist for them). Everyone else might receive https://steamdb.info/sub/372953/ which can be redeemed everywhere except China, Hong Kong, Macau, Taiwan

https://www.humblebundle.com/games/close-combat-collection
Chronicon - https://steamdb.info/sub/69390/
Dungeons of Sundaria - https://steamdb.info/sub/151888/
Blossom Tales II: The Minotaur Prince - https://steamdb.info/sub/626428/
Into the Necrovale - https://steamdb.info/sub/614839/
Dwarven Realms - https://steamdb.info/sub/973600/
BloodRayne: Terminal Cut - https://steamdb.info/sub/481760/
The Last Soldier of the Ming Dynasty - https://steamdb.info/sub/897672/
Ghostlore - https://steamdb.info/sub/640301/

3 Tiers.