I think this is doable, but it kinda depends on what you define as being offal in that it is probably going to be easier to get things like the "mainstream" organ meats like liver into a level of higher popularity than the more fringe things like, say, brains, "oysters" and "bull sausages" because of the sheer strength of the squick factor in play. Something like liver is pretty low hanging fruit (ie, liver and onions is pretty well known even if not that commonly eaten nowadays) and kidneys are probably the next easiest, as you've got steak and kidney pies over here in the UK that show a pretty good way to get it across the line into a more mainstream form of food. Stomachs seem harder (perhaps the presence of a large Scottish immigrant community in the USA manages to establish haggis as a Scottish-American food?), but the hardest organs are going to be the ones people just find weird; I'm not sure how you could get eating brains into the mainstream (
maybe you could get a short lived phenomenon of it from something like a far more popular Dawn of the Dead, but I doubt it), but things like intestines, trotters and tripe are going to be an even harder sell.
I think you could potentially get a sort of PoD to get this into the food culture of the USA during something of a major economic downturn/agricultural production problem (a question I leave to others more familiar with the details of American history to figure out) where larger and larger amounts of the population are willing to buy cuts of meat that they might've never considered in order to get themselves at least some kind of protein on the table. You'd need that time period to hold long enough not just for people to start to get used to the idea of eating organs (and for their children to get used to eating organs) but also to allow the popularization of the stuff in cookbooks and the like, which'd be how you break it into the mainstream. A lot of different cuts of meat as a whole can end up being proper naff if you've got no idea what to do with them, but give them a good amount of seasoning, the proper herbs and spices and the right cooking method and they come alive. The same thing holds true to offal, which a lot of people wouldn't know how to cook properly so they'd be stuck in the dreary grey phase either til they stop having offal (and probably never touch the stuff again) or til they figure out how to cook it in a way that lifts it up and shows what it can do.
It's that second one that you need. If you can get that off the ground, you've got better chances of seeing the stuff break out. It'd never be enormously popular (I don't see Kentucky Fried Trotters or Liver King becoming a thing), but it'd still be far more popular in that timeline than in ours. Probably. Does anyone have any statistics on the amount of offal getting eaten nowadays?
Midlander from the UK: they're nice, but finding good ones can be an absolute pain in the backside. They're the kind of thing you need to go to a butcher for rather than just trying to buy frozen (which tend to have weird amounts of breadcrumbs in them and can make them look like a very sad teabag), but all the butchers around here are really,
really dodgy. Like, using sauce to hide the fact that meat has gone bad levels of dodgy. They're nice, but they ain't playing Russian roulette with food poisoning nice