He drives the project long enough that probably no b2 code remains. He could have prepared and take a contributor agreement or some other measures to allow relicensing.

Question however is, whether auch a scheme would have made WordPress successful, or if it thrives from the community, where many assumed that everybody plays on the same field via GPL.

Using the GPL is not racketeering. Why would any user expect more rights than a contributor?

He can also just stop open sourcing his company's work on the product. WordPress is GPL, not AGPL, so they can make any changes you want and use them on Automattic's platforms without ever releasing code to the community again.

I don't understand your point about forking, yes they'd have the GPL but so what? They can control their fork from then on, it doesn't matter if they have to continue open sourcing contributions, in fact it'd be preferable to whatever Matt is doing.

I think you underestimate the work it takes to maintain and more importantly grow such a large open source project. If wp engine can barely contribute today, what are the chances they want to take on the whole thing. Nope they just want to get rich off open source. That's understandable , they are a for profit after all. But at what point does it make sense to give back in terms of either money or time to make improvements to the ecosystem that you depend on.

I agree with Matt's ideals but not the actions. The reality is theres not a whole lot he can do without looking like spoilt kid taking his ball away from the game.