At the time of writing, it has only implicitly been mentioned in the comments here about the security risks this OS might have.

We know that Google has a very close relationship to the US government w.r.t surveillance.

Apple claims to be "fighting" it, whether as PR or genuine.

Huawei on the other hand is deeply intertwined with the Chinese government and their policies should give an indication that backdoors and total surveillance will be passed into the OS.

I don't see this OS succeeding beyond China though. US companies still dominate the app market outside China. No WhatsApp = no thanks; to the majority of the developing world.