I'm bouncing around to too many discussions today. I think this summation by loligo speaks to your question about skipping waves:
"I think that in the history of slash this was a progression because fandom as a whole couldn't get to stage 3 without going through stage 2. But I don't know that stages 3 and 4 necessarily count as "progress", in the sense of improvement. I think they're just different kinds of engagement with stories and with fans -- kinds of engagement that aren't open to you until you've spent some time in fandom.
I think you can definitely return to stage 2 at any time -- for the length of a story, or even as your primary mode of engagement in a particular fandom. But I think you only get one first time: you can't go back to stage 1. Once you've seen context, you can't unsee it. Also, I think it's possible for new fans to skip right from stage 1 to stage 3 these days, now that our fannish foremothers have done the collective work of stage 2."
Keeping in mind that this was written in 1996--it's possible that some newbie fans and writers still go through wave 1 (it seemed as though some brand new to slash Firefly fans did, though the show was pretty loose in terms of sexual identity for its characters), it's more likely that they'll *read* first and second wave stories and then jump in with a more contemporary voice.