The privileges page for Meta.Stackexchange.com (MSE) lists "Participate In Meta" as a privilege. I think that it should be removed as a privilege on MSE (unless we get a meta.meta.stackexchange.com per site child meta, which would be awesome ;-).
The privilege exists here because it has to exist here. Now that Meta SE has split off, it has become the source site for all the privilege wikis across the network, so the privilege and its wiki has to be available here in order to be that source.
So the real issue is exactly the same as the duplicate question you linked (the split of Meta SO and Meta SE makes abslutely no difference here) - the privilege should be changed to 1 reputation because anyone with an account can come post here. They already do the same thing with the "access review queues" privilege. That privilege is normally granted at 500 reputation but since the review queues mentioned in the privilege don't actually exist on meta sites, it was bumped up to 2,000 reputation here, because that's when you actually gain access to your first review queue here. They can't just remove the privilege, because they need it to be present.