Being a racial minority in another race's nation is a shitty deal. There's really no way Europeans would want to willfully become a minority in any European diaspora nation, and why should they?

The fact that Europeans have been essentially "ruling" (at one point literally, and in a more modern sense: that other races have been forced into European political/cultural systems) over other races in the "New World" has created an underlying Euro-resentment (which is clearly completely justified). The worst thing that white America ever did in the post-Revolutionary era (for everyone involved) was open the gates to South Indo-Americans, Asians, Africans and Arabs. Once modern minorities become the majority, and political power shifts, white people will fall victim to this resentment. If white people think they're being treated unfairly right now (lol), then just wait until 2050.
Multiracialism is a farce, and the nation in which it takes place doesn't matter.