There is none because forking the code doesn't automatically bring the community along with you, and so no one wants to risk the instability that would inevitably come from forking. When a project needs a fork it usually much more closely resembles a civil war than it does a succession, and the whole system becomes weaker because of it.
Why would we start with a model that we know will permanently weaken our community when we inevitably need to trigger a succession?
If the WordPress idiot was like "I'm going to make WordPress worse, and I don't care what anyone thinks", there would be a fork. But that's not what's happening. What's happening is that one WordPress host (the official one) is miffed that other hosts aren't paying a tax for the use of (100% open source) software.
That makes the guy in charge an idiot who doesn't understand OSS, and his idiocy is helping to destroy his entire company ... but he's just being a bully: he's not hurting anyone's use of the software.
Ergo, no fork.