I'm not sure where you got the take that the left thinks of it as trauma; it's consequent events (e.g. your ancestors could not get an education, job, and/or buy a house because of racism -> you did not benefit from generational wealth even though there is now less racism).
I'm also not sure where you get the far right idea from; I don't think they believe in "a sort of cultural memory", it's just culture, nothing woo about it.
TL;DR it feels like you're misrepresenting political sides to try and make this article about politics.