Vincent Baker is very on board with the fluidity of PbtA. He gladly lets people use PbtA to describe games that have no resemblance to Apocalypse World. And he's even said that his own non-AW games like Mobile Frame Zero Firebrands are PbtA games because they are building on game design theory first presented in Apocalypse World. I'm paraphrasing a bit, but he's pretty insistent that PbtA is a school of game theory and not a system.
I have no idea if Avery Alder approaches Belonging Outside Belonging the same way? I haven't read Dream Askew, so I don't know if this specific thing is addressed in the book. Mx Kit has mentioned that there is talk about how you can change things but that's sort of different. Does Alder consider BoB to be a system? Or does she consider it another thesis on game design to be further developed and built on by community?
Either way, my favourite PbtA games are the ones that don't even remotely resemble Apocalypse World. Like Wizards Aren't Gentlemen for example is absolutely bloody fantastic. So yeh, make BoB games that don't resemble Dream Askew.