It was handled all wrong. The people that cared wanted the update, the people that don't care won't notice, except their armor lock won't be as game-stopping now, god forbid.
Even the Vanilla/TU division was handled wrong. If they were going to do the split TU thing then have an actual split. Keep old playlists Vanilla, make all new ones TU. What do they as one of their first moves? Introduce TU to Multi Team, which is an AR start playlist with Rocket Hog Race. Because people really wanted bleedthrough in fucking Rocket Hog Race.
Then they put the TU on BTB, even though there was ALREADY a TU BTB, so now your two semi-redundant lists are truly redundant, as the choice was removed. Then TU'd Rumble Pit, so you didn't have a choice between playing TU in Anni FFA or playing non-TU in Rumble Pit.
Then they introduce a new playlist in Squad DLC, and it's.. Vanilla?
At this point, this is your choice for non-fringe/specialty Vanilla Reach:
Team Slayer
Squad DLC
This is your choice for non-fringe/specialty TU Reach:
Everything else
Seriously. Two playlists. Why is Vanilla still around? Remove the stupid TU acronym from the gametype names because most of your playerbase doesn't even know what TU means, make the TU global, and actually accept and take the criticism and ragequitting from players that liked Vanilla Reach, just like Bungie had to do when they made the Halo 2 TU and the Halo 3 TU. Drop the cool uncle bullshit.