No, being "neutral" is not "taking a side", that's the definition of the word. If you pre-moderate you open a whole can of worms. What will they ban next? This makes me not want to use Codeberg ever because it's not plannable.
Clearly some things are harmful enough that they should be banned.
Many of us are capable of more nuance that that and don't apply the label "slop" to everything where generative AI is involved. The linked Mastodon shows no nuance, and neither does your reply.
Two things can be true at once: GitHub has degraded into a "slop" cesspit and that agentic tooling has legitimate use cases.
Finally people can also legitimately object to a host mandating what tools can be used in authorship even if they don't particularly care for those tools themselves.