I agree. The sequence from being cautious to being fascists is not new either.

In practice WW2 destroyed the credibility of eugenics and should have made it easier to discuss these things since ordinary people find it instrinsically distasteful. Plus eugenics was always an elite idea. But as you say they went overboard so every dry examination of group differences in IQ in some obscure paper became a new Mein Kampf.

As with all these things all it has done is draw attention to these topics.