the unban itself federates, but on community bans the user gets unsubscribed from the communities, which deletes the associated subscription in the db.

skimming over the code it seems to be only happening in case of community bans (including the ones derived from instance bans on 0.19), but it should also remove your local subscription on your own instance. as long as that federates it should still be picked up by lemmy-federate eventually, as your local instance should also have removed that when receiving the community ban.

it might be debatable whether subscriptions should get removed with community bans for public communities, but overall the code logic seems to be there. i haven't tested this end to end yet.