Well we certainly consider it an important aspect! But also, as said, we were standardizing the existing set of federation functionality currently implemented in the federated social web.

But the Social Web Incubator Community Group has made anti-spam/anti-abuse stuff part of our mission, but that's hard stuff. ActivityPub does include federated blocklist support, but I think it's not enough. I've written about possible directions though: https://dustycloud.org/blog/possible-distributed-anti-abuse/