halo combate evolved confusion

I was wondering in online matchmaking is it like odst where you played with people from halo 3. So if i get combat evolved do i get the reach maps as well for online and all the dlc maps or do combat evolved players play seperate from reach players.

As I understand it:

Halo Reach players with CE:A DLC will access the Anniversary Playlists using their disc through the Reach Matchmaking menu.

CE:A players using the CE:A disc will enter Reach MM and only see the Anniversary Playlists, not all.

All Reach/CE:A players will be in the same pool for Anniversary Playlists.

I wonder if they will make other map packs and playlist available for purchase for halo cea because i traded in reach.

I was wondering the same thing…I have a decked out Reach character model on which I’ve spent considerable XP, and I’d like to buy the Reach maps to expand the variety of CEA…also, any word on whether SWAT will be in CEA?