It doesn’t strike me as realistic at all. Queer people need to be able to deal with heteronormative people as much as the reverse.
Otherwise you’re just self selecting into ghettos. I don’t think it can really be avoided, but to present it as desirable strikes me as wrong.
That is never going to happen if you’re not part of that outside world. Queer people should be normalized, not hidden. Though it’s absolutely true it’ll suck for the ones alive now, it might make it better for the ones born three generations from now.
The idea isn’t that marginalised groups should hide and not mingle at all but that they should have a refuge they can retreat to because the outside world is too harsh right now.