Well at least for that particular client's case, it was consistently inconsistent.
Yes. The problem that prompted this was similar: one of those quirky things that is there so long if you take it away things break. Orphaned activities is the same deal: after all these years, if you fixed it, half of Moodledom would break.
I think each LTS version should have NO new features at all. But that six month period would be dedicated to just normalizing.