Bought the game (not from the bundle), and the game claims there are currently no Steam keys. Do you know when those'll be resupplied? THanks.

Jet-combat roguelite, occasionally with swords and 300+ other items to strap onto your jet. · By
Itch did grant keys to bundle users for the current bundle, I don't think this was intended and it immediately depleted my keys. I'm waiting to hear back from support about this before I'll add more keys.
I can only provide Steam retail keys for users that get the game under similar conditions as on Steam and until I hear back from Itch I can't guarantee that.
Itch did grand some on accident and removed it for further purchases, but the claim stayed for people who bought it while it was configured wrongly.
I'd assume Steam ain't gonna force you to give away your game for free because of, essentially, a pricing error. I mean, those happen regularly, get corrected, and none of those game thereafter were as cheap on steam as during pricing errors.
But the concern is understandable. Sorry to hear you're having to deal with this!
Well the bundle used to say "16 steam keys included" and listed them; it doesn't say that anymore and has no steam keys listed. Their docs also mention that they generally turn it off for charity bundles, meaning this was most likely an accident. https://itch.io/docs/creators/bundles#hosting-a-charity-bundle .
"Generally, for larger bundles priced lower, we will disable all access to External (Steam) keys to prevent participants from having to generate an unrealistic number of keys. "
Admittedly the part about claims staying for people who bought it is conjecture from reddit discussions & some people here complaining about not being able to generate steam keys from their purchase https://itch.io/t/5910207/cant-find-my-steam-keys-anywhere#post-15462771 and from vague memory of a previous instance where that happened.
Additionally, here's a discussion where someone got the bundle later mentions not finding any steam keys. https://www.steamgifts.com/discussion/z00yf/itchiosteam-bundle-charity-bundle-no... (some other people in the thread mention not getting steam keys with the purchase as well)
Not official sources and all, but hopefully all this allays your troubles somewhat. =)
Hope you get an official reply soon too.
The person who found no indication of keys would then have found a steam key claim that simply says "There are no keys available at this time, try again later" when clicking the button, instead of nothing. Additionally, attempting to buy the bundle currently clearly says no steam keys, which it didn't before :

But again, fair concern, you're right to wait, and it's rather unfortunate of itch.io to make the mistake and then not reply to you.
Good luck with this! And with your future games, you make pretty cool stuff =)
outsider opinion on this. in my experience with itch they remove steam keys around the 25%-33% mark. There seems to be a lack of awareness from devs so im assuming either this was a fine print thing or itch did whatever they wanted.
The problem: since itch promised keys at the time of purchase up to about the $25k mark i imagine there are around 2000-2,500 key request. Due to EU laws I think itch is forced to uphold the purchase for everyone so when you go to fill keys there are probably 1000-2000 people checking daily/hourly. So interested to see what happens here because if itch nulls the key claims they could be legal liable. not sure though, not a lawyer. subscribed to the thread.
Hey, would love a steam key / reload of keys! But yeah, i get that you want to make sure, about the circumstances / what has to be done etc.
I also had one game steam key purchase in a bundle, where a game-dev (AIdol: Artificial Intelligence Idol) refused to restock the steam keys, because he said he was included on his own will / behalf, but he said, he didn't realize how many purchases and steam key requests there will be, so he got overwhelmed and couldn't supply it. And though it's a bit shitty, because purchase is purchase / breech of contract - i still get these problems for devs, as far as i know, it's now more reglemented, how many steam keys you can supply apart from the steam store?