I'd rather Oceania join Asia and split Asia into West and East for qualifiers before a top six fight it out for the top four spots
We'd be fucked, no way would we top Japan, South Korea or Australia in an East Asia group. If Oceania joined Asia the qualification structure would be hardly changed anyway. My bet would be that seeing as the first round of Asian qualifying consists of all the Asian minnows playing their minnow neighbours, theyd find a way to incorporate all the current Oceania members into this stage by playing each other, with the top 1 or 2 sides progressing directly to round 2.
The Caribbean Cup still lives on in concacaf so theyd probably continue to use the Oceania Cup to give these sides games, or even use this as a qualification path as we do now
No way would AFC split in half all because a bunch of Oceanian nobodies become merged