I would submit that a larger component of this “organ meat” thing was that the organ meats were not rationed as severely as “normal meat”, and as such, they got eaten as substitutes. Once the market came back, most people abandoned them as being “old shames”, and they never went back. I can remember my grandparents serving liver in the 1970s, but among my peers, such a thing was utterly unheard of. Had friends over for dinner on several occasions where that was served, and the response from them was not what I’d term “enthusiastic”.

Why tastes changed? No idea. I’d lay out, though, that “marketing” had damn little to do with it, and that the “government meddling” probably had success only in their own minds.

What about saturated fats? I’d call that a pretty substantial change. The idea of Canola oil was completely unheard of before the push for non-saturated fats, and now it’s a staple (as well as other vegetable based oils).