Don't know about 343, but with bungie, the only way to play them in other playlists would be if everyone else in your game has them to... Also, to play in premium, you need BOTH DLCs. As the matchmaking system doesn't prioritize (as far as I know) searching for players who also have your DLCs, the chances of finding a full game of people with the DLCs is quite slim. Especially on large team playlists. This is probably why you never see breakpoint in invasion (though I'm not sure).
Frog, these two were part of the Defiant Map Pack, along with the firefight map Unearthed. It costs 800 Microsoft Points to buy. If there is a star next to a map in your local files, you don't actually have it. If you can go into forge on it and you didn't buy it... then I have no idea how you have it, someone must like you or something.