[Fanatical] Purchases qualifies for 2-pack of mystery keys..from where?

I decided to pick up Lovecraft's Untold Stories for 4.99€ in Fanatical's current (as of posting, about 20 minutes remaining so hurry up if you're interested) Star Deal. I'm a fan of the genre(s) (Cthulu mythos and Rogue-lite/like) and it has very positive ratings so, why not.

That's not the point of this post though, the point is about when checking out to complete the purchase you now seem to "qualify" for the "opportunity" to quickly add a 2-pack of mystery keys for an additional 1.99€ each. I decided to be irrational and roll the dice. Got these (praying the chart works as intended):

Retail:

• $27.00

CV:

• 4.0500

Chart created with Lex's SG Chart Maker

As a mystery key result, this wasn't terrible. Don't know about Supreme Ruler but Renowned Explorers alone made it feel like a win. If I stumbled upon Renowned Explorers in a Steam sale for 1.99€, I'd definitely consider buying it.

I can't find either of these games in any Fanatical mystery bundle charts which implies these mystery keys are pulled from a different pool entirely. Anyone know anything about this? What games are in the pool, what games are people getting? Are these just left over keys from old Fanatical bundles? (Renowned Explorer has been in 3 Fanatical bundles previously and Supreme Ruler in 1)