This doesn't have much impact for Huawei users I don't think. Huawei will be pushed to develop their own system I believe. It'll be worse for users since they don't have the expertise to do it. Growing pains etc. But long term if they are able to get through it, it'll be better for them. In China they couldn't use any google apps anyway, so Google doesn't care. Maybe they still got paid for using the OS? I don't know.
Xiaomi is so far behind in China it's not even a competition. BTW XIaomi's MIUI is still based off of Android, and most recently Android P, so it's not like they don't risk Google pulling from them too. This will result in a branching off of Android or a creation of a new mobile OS. Kinda scary since it even took Google many years to come up with something more reliable. Mostly this just affects users in China anyway, since Users in US is mostly Apple/Samsung/LG.