No, they really aren’t “all White”, unless you’re talking about rural communities, and in those communities everything is so spread out that the only time everyone comes together is at the annual local fair or while the kids are at school, so it’s really nothing like a white suburban community. In the 1980’s, the vast majority of suburban communities were 95+% White, it isn’t like that anymore, and that was just 4 decades ago. There are no laws in place designed to protect the demographic makeup of any predominantly White community in the U.S., and it’s not like mass immigration from brown countries is finished all of the sudden. The browning of the U.S. will continue because it’s intentional, tens of millions more will come across U.S. borders, and the cities are already pretty full, so they go into suburbia now, and then once those communities become minority White, even the rural communities will be browned.