Eight was the number I had heard. (No, I'm not just taking the next step in your number pattern. That's really what I heard NAMBLA wanted.)
I think the ‘8’ comes from the possible NAMBLA ‘motto’: ‘in before 8 or it’s too late’. Not kidding.
I don’t doubt it. It’s about mainstreaming homosexual pedophilia (which will be a lot easier to do than heterosexual pedophilia). Gays have tried to separate themselves in the past from those preferring men vs. those preferring boys, lest they be linked to pedophilia and harm their “cause”, but they’re just approaching things in incremental fashion. Like the old Cole Porter song (a fag himself), the goal is “Anything Goes.”