Thanks, interesting discussion.
I can see how it could be annoying if it grows to the point that mirrored posts and "user" bots dominate the feed. But I can also see the main usecase being potentially of value to some users here that may want to follow some specific reddit content.
Since this is not an issue that requires immediate action I think it is better to wait and see. Instance blocking at the user level will become available soon, so for something benign like this I'd rather leave the decission to the users.
I do agree that this is something to pay attention to, as something like this at scale could indeed become a problem. But I am O.K. with waiting until it does become a problem... What I have already seen many times is that theoretical future problems end up never materializing.