They are not categories, they are contexts, and educational texts can have value within any or all of those contexts. In fact being educational or informative could inherently be considered to be of literary value.

Many people rightfully complain about the lack of specificity and clarity in the third prong, but that is even more evidence for why it is a bad community note because there is obvious room for interpretation and the note leaves none. Thus, even if you agree with its conclusion, it lacks sufficient context which is one of the voting criteria.