This feels kinda' like a bug but I think it's more of a quirk in the program working as the settings dictate, but it feels a bit awkward that notes whose last edit was long enough ago it's outside the note history window lack the protection against accidental deletions/etc ones within it would have.
I did find one topic from almost two years ago requesting the option to keep revisions as well as or instead of X days of history but there was no response and if there was some other similar topic I missed seeing it when searching for "note history". Something along those lines would handily de-quirk this quirk, or even just some sort of "ghost" note history that keeps a revision for a couple days (if note history is enabled) just in case would also work.