It's time to fork it
Though given how little those companies have respected their users so far, I feel like this is a bit of a monkey's paw.
In a way, it's similar to Samsung's Tizen, except Huawei's OS sees actual use, though not so much in the ecosystem of the USA of course.
That's the huge, huge carrot that Google carries in front of everyone thinking to fork Android.
Google does have a card to play here, I don't disagree but they shouldn't overstate their hand either. The Google bits of Android are good enough to keep open-source ROMs and small manufacturers away but they aren't a silver bullet and won't save them if China stops playing the game.
I highly doubt that. People have far too much money already invested in Play Store purchases, that's a lot to give up for a marginally cheaper phone.
Also, I don't necessarily think the phones will be marginally cheaper, just that the market will adapt.