A bit confused about levels

Probably Shadow Warrior being put on the bundle list recently, since everything else you've given away was either bundled or >95% off.
Yeah, it seems silly, maybe you could derive some info from this thread...

I was pretty sure this didn't affect your LVL status because the giveaway was made before.

You would be wrong. Games that are retroactively bundled to a certain date will reduce your value after the bundle date.

Steam Store price cuts will also reduce your value to the current price.

Shadow Warrior was set to bundled with november 2014 as starting date (iirc). So all GAs made after that date are now counted as bundled.
It goes like that for all games that get added to the bundle list. Every GA made after the set date has its CV changed.

I know the base prices for games can change, but I was pretty sure this didn't affect your LVL status because the giveaway was made before

And that's where you're wrong. If you giveaway Fallout 4 today, in a year-or-two you'll have $30 CV and in 4 years you'll have $10 CV (or whatever US Steam Fallout 4 price will be then), as it is counted by today's Steam prices, not by date-of-giveaway made prices.

But in your case it's Shadow Warrior, which since last day or two is being counted as bundle game for every giveaway made since November.

I think people should use search feature for forum more often :P