I don’t think it is about danger of “extinction.” But fast-food has been kind of a big deal for better or worse, so maybe it would be ok put a McDonalds on there?
Note that this particular article is about fairytale castles, so not real castles, and a slightly more unique thing. But there are real forts and castles in the thing as well.
We could possibly worry that fast food is not really worth commemorating. But then, historical forts and castles were sometimes put there for all sorts of nasty reasons, so I don’t know what’s disqualifying.