It's fairly safe to assume that all third party reddit apps will be shutting down. The price they've been quoted for API access is simply too high, and I don't think any of the devs are rich enough to keep it running out of their own pockets. I wouldn't be surprised to see some apps try to stay up, but I highly doubt they can last long term.
Either that or they'd have to start charging each user tons of money, and/or disabling free users entirely.
In the recent AMA it was said that apps that focus on accessibility might get free access, but based on what devs are saying about having trouble getting in touch with anyone at reddit, I wouldn't get your hopes up.
I mean, why not just use PopOS? It's not my first choice but a lot of people like it.
Fedora is the other obvious choice, perhaps even silverblue for that nice immutable ecosystem if your apps can all be obtained via flatpak.
I also really like endeavour due to how minimal it is out of the box an AUR access.