I don’t love tests like that either, but I’ve seen a lot of them (long before the generative AI era) and heard reasonable people make arguments in favor of them.

Admittedly, in the absence of halfway competent static type checking, it does seem like a good way to prevent what would be a very bad regression. It doesn’t seem worse than tests which check that a certain property is non-null (when that’s a vital business requirement and you’re using a language without a competent type system).