I'm kind of cheating here by answering a slightly different question than the one that was asked, but I think it's weird when secondary titles tell stories with huge ramifications that then doesn't affect the other titles at all. For example, a few years ago there was a secondary Batman title called Batman: The Dark Knight, in which Bruce Wayne met a new girlfriend who was then murdered by Mad Hatter, and it was never acknowledged anywhere else in the line. If it had happened in the main title it would probably still have been a tired story trope, but at least I would be able to buy it as something with a bit of narrative heft.