Current generators like ChatGPT are also (at least until very recently) bad at rhyming, especially over a long work. This is because they generate text completely forward and can't based early lines on what later lines will be. If it is the least bit melodic or comparable to a normal song in meter, it is almost certainly not produced by a current gen AI. Some of the newest ones can do it better, but they are expensive to use and it is unlikely a reddit rando is using it unless he's also a researcher.