The rich whites and Asians will just send their kids to universities abroad, get a better wider education and then be even more advantaged over the under performing groups.

That's what's happened when groups have been excluded from higher education before.

And people very quickly seem to forget that mixing with better performing kids lifts up the poorer kid's grades. If those advantaged kids disappear the results of the other kids will go down no matter how many free chances they give them.