if i have dlc and my friend doesn't, can i still invite him to my party?
or does he get booted when new maps come up
You can still invite him, you just can't play the new maps with him/her
So what happens when new map is next they get booted?
If he doesn't have the map pack, it puts you in playlist with only ppl that doesn't have it. There will never be a new map next with them in your party, new map pack is disabled for everyone in your party!
Is that why playlists is empty now cause not many people have dlc yet
No, the new map just won't show up on your playlist as long as your partied up with some that doesn't have them.
So let's say there's only 100 people who bought dlc those 100 will not be playing with the rest without dlc?
I Beleive that's correct. Never really knew 100% how that work. But I do think it's something along those lines.
If you purchase DLC and you and friends join your lobby that don't have it. 3arc has a message in red that will be posted under the create a class, scorestreaks, barracks, and leaderboard options which states....
PLAYERS IN THIS PARTY DO NOT HAVE THE SAME DLC MAP PACKS.
MATCHMAKING WILL ONLY SEARCH FOR MAPS THAT EVERYONE OWNS.