I doubt it (even though I run a dev shop w/ Vietnam based engineers). US companies will continue hiring US based engineers. And when Covid is over people will go to the office again.
Also wanted to add in developed countries (and by corollary, big cities) it is very hard to make friends once you are an adult. When I lived in Vietnam it is 10x easier to date/make friends/get involved in the local community (vs NYC,LA or SF)
East/West can work well as well. I have a team in Vietnam with USA clients and we just do 1h overlap per day. Too many meetings may not be a good thing.
I am here in Vietnam (and was in California a few months ago) and the difference is day and night. Lockdown is super strict here. Everyone wears mask (even when it is only a few cases out of millions). It is a 21 day mandatory quarantine (if you get approved to get in). The results speak for itself.