I don't think the Aryan invasion theory was appropriate to justify colonization, but I'm also not sure this constitutes evidence against it. In any case, Sanskrit is far more archaic than Hittite, and even with the genetic evidence it doesn't make sense that Hittite would precede the Indo-aryan languages.
The Bhagavad Gita is quite clear about the cultures of the old Aryan peoples. They were nomadic, cowherding peoples, who were highly patriarchal, that valued prowess in battle and the ability to kill your enemies ruthlessly, even if they were members of your own family. They were probably white because Tocharian speakers in western China are depicted in cave painting as having blond hair and blue eyes[0], a group of people who completely split off the rest of the Indo-European tribal peoples well before they entered the subcontinent.
Is Nazi race science as a justification for brutal genocide and the destruction of labor organizing something I agree with? No, but the Nazis understood that anyone can spin a story to justify any political regime, and that whoever is in power is constantly inventing their own histories to justify their power. None of these things are very meaningful, in the end. Language, culture, and history is far more diverse than the question of Yamnaya genetics.
[0]https://en.wikipedia.org/wiki/Tocharian_languages#/media/Fil...