Sounds like you have a great opportunity to collaborate on technical details, etc.. but still have separate projects. More power to you!
Now if you got more specific and the other author happened to have beat you in a student council election then I'd say it's probably time to forgive and forget.
When I joined there were a ton of posts recommending that you just aggressively follow people (in a positive way) and that's led my feed to be full of artists, photographers and writers. Which has been awesome.
I don't know if I'd want to hop back into using an algorithmic feed and, as you note, it'd probably become trash pretty fast.
I think the desire there is the faster you can replace a mainstream site the faster it'll go down.
Also, it's hard to deny that part of the draw of social media is following/interacting with certain people, so if they move it makes it even easier.
I remember just sitting there after helping the first spirit depart and thinking - wow. Which doesn't happen a lot in games, but the combination of the music, the storylines for each spirit and the time when I started playing (early in the pandemic) cemented the game in my mind as a piece of art.