There is a substantial amount of spam and NSFW posts on the All page coming through already. Most NSFW posts aren’t being tagged as such and are coming right through. I am not sure how this can be weathered but we need something in place fairly soon, I feel like we are days away from rivers of bad stuff, especially via some of the federated instances.
EDIT: I personally don’t care much about the NSFW aspect, more in the lines of what a newcomer will be seeing when they get to the main page. 99% of the newcomers don’t know / care about federation and have no idea how to turn that off. Liability for the server owner is also an element of consideration.
I think defederating may be knee jerk at this stage? Beehaw seems to have defederated because they vet users and are worried about unvetted users flooding their service; that’s a fundamental community position rather than a fediverse issue. In this case it’s more about tags not being applied correctly and how to improve that process (e.g. automation based on server or community posted to).
Defederating or blocking specific instances/servers seems like it should be a last resort - e.g. if a service is lax about moderation or refuses to deal with issues then it makes sense.