This would also set a level field between beef tallow and other oils. I would expect that a lot have changed in the fast food industry supply chain since the "good old days". Frying oil is only one of the factors that may have affected the taste of fries. Not to mention that everything tastes better when one is young.
This is the legitimate end of the spectrum. The science that drove tallow out of kitchens and homes was incomplete, particularly when it was replaced with trans fats.
Where it goes off the rails is when nutters conclude that because tallow was wronged in one context, it is wronged in all of them, which leads to folks rubbing tallow on their faces [1]. (It's probably harmless. I've used it as a foot cream because I got samples at my farmers' market.)
[1] https://www.prevention.com/beauty/skin-care/a63833046/beef-t...
The amount of sugar added to prepared food took a big jump around this time, as it replaced fat to make the food taste good. Around this time is when obesity started to become a bigger problem.