I’m in the same boat as you, no word yet. If I go back to the reservation page, I do have the option to cancel my order, so presumably they at least have my place in the queue.

UPDATE 05/26/26: I was just able to complete the purchase. Valve sent me an email and I was able to purchase through the Steam store.

+1 for Bazzite! I converted last year, and have never had to go back. My tip would be to make good use of ProtonUp-QT that should have come with Bazzite by default. Use it to get Proton GE which in my experience has been the best compatibility layer for Steam games. You can also batch update with that tool so that when a new version of GE comes out, you can set games en masse to the new version.