Sausages, huh... For Japan, meat is a relatively modern ingredient. I think the closest thing they traditionally have to a sausage would be fish, kamaboko – but then again, initially they were still more like fishcakes? Anyway, if Gensōkyō was sealed off at the onset of the modern era, then this dietary restriction should still apply for the villagers.

But then there's the fact that new outsiders do settle in the village, who would certainly find it normal to eat beef and pork. I think some manga chapters also show villagers being served meat dishes? Gensōkyō is also in the middle of the mountains, so the villagers definitely hunt game. And despite the historic official ban on meat consumption, people did eat meat anyway even in urban areas. Huh... there are jargons too you'd find in restaurants.

Sakura is horse. Momiji is venison. Ichō is duck. Botan is boar. And Kashiwa is chicken. Pharmacies even sold meat as not "food" but "medicine" lmao. Lots of allusions to the prohibition here.