I really don't think that is the case, but I'm interested to hear why you think it is. In my understanding the community is not controlled by a central authority.
The rules for how Wikipedia is edited are ultimately set by the people who run Wikimedia. They have the final say. It's a centralized service (there is a single Wikipedia at a singular domain, being the sole source of truth).
In the context of this discussion, there is no such notion of a federation of wikis on various hosts contributing to the content. There's obviously no decentralization of Wikipedia.
