Whats is going to happen in 24hours? 48hours?
Short Term Impact
I think the first 12-24hours will drive many users into confusion. The lurkers will switch over within the first 1-2days, the active community will split up, some remaining on multiple platforms (incl. reddit).
Medium Term Impact
Reddit lives from it’s moderators. But nowadays a good AI might replace that, will have a rough start but gradually become better. I still believe the communities will become streamlined and heavily automoderated due to lack of human reason. That will hurt discussion, conversations and though provoking comments.
Fediverse
The Fediverse will definitiv gain from this. Reddit will not see an immediate fall but gradually decline. The majority of users will mostly be lurkers.
What if…
BUT, with no API, no bots… Maybe, this will actually work out for reddit and a more active community will build up again. There 's always the option for a black swan of any kind.
I think there’ll be a similar amount of users to begin with but over time a poorer quality of moderation. People who want quality will experiment with other places like here until something takes off; the others will stick around for the memes.
What it will live or die by is whether its niche subs keep going or wither on the vine. Its big subs like music, gaming, funny, can be replaced by literally any other social media next big thing to take off. What still attracts people to Reddit is the ‘oh, there’s a sub for that’ hook.