I thought Theosophy was into all that Aryanism anyway, with the whole business of the next root race coming from the Aryans?
Just wait till the Nazis get hold of reproductive tech- oh wait, we're already at that point. There's nothing stopping some wealthy Nazis from ordering up a few dozen Aryan superchildren from a catalogue. By the egg and sperm from highly intelligent, athletic, good-looking Nordics, and rent a womb from some poor woman, then give them to good Aryan families to raise...
Ironically, what made me think about that possibility was a quote from Harry James Potter Evans-Verres about Lucius Malfoy solving the problem from his end, by adopting aggressive pro-natal policies for pure-bloods - ironic, because the author of Methods of Rationality is Jewish.
Anyway, give the new Ubersmensch advanced technology, and you've got yourself Nordic aliens.
Seriously, just because eugenics has been defunded, it doesn't mean it's been made illegal. It just has to be done with volunteers. Or by pressuring women to have abortions...