I’m sort of confused as to why they don’t just make the mappacks free now. This would make matchmaking better for all. The new maps would be able to be played more frequently in playlists like Team Snipers, Swat, and Slayer. Map selections wouldn’t look so terrible as they do in those playlists as well. Imagine some snipers games on Breakpoint or Highlands. It would be a refreshing change from Hemorrhage. Team Slayer would get Condemned, Tempest, and Anchor 9 to show up instead of those silly little grey community maps. Invasion would add Breakpoint to its lineup of maps immediately, and I know many people out there want to play on this map more for that gametype.
I am positive that some mappacks were made free in Halo 2 (and probably Halo 3 in some cases). I’m basing this off my memory, but I could be wrong that not all Halo 2 map packs were made free, just most of them.
Still, it’s too bad that the only playlists that you are guaranteed to play the new maps are Premium Battle and Premium Slayer.