If an instance become overwhelmingly popular it could theoretically decide that users from other instances aren’t important and leave the federation. They would lose the users from elsewhere, but leave them free to fork the code and do their own thing. I’m not sure how this works with the licensing, but they were determined I’m sure they could go down the same path as Reddit.
Whereabouts did you come across this beast? I’ve done the JDF a couple times, one of my favs.