Having new maps/weapons is cool I like what they added for HALO 3, i don't care for customisations and weird colors has I've turned them off, nostalgia maybe, It's so bonkers to think this game was a train wreck at release and they abandoned it for years before fixing it and improving on top of it in recent times, it has to be done though it's HALO.
Imagine this with an Gears of War collection or Call of Duty collection (with proper remade graphics assets) It's so great to play timeless classic multiplayer game like Halo 2,3 with modern console/PC with an active playerbase and support from it's devs, that kind of stuff NEVER happen especially for console games, you have your usual DLC / support for months / 1 or 2 years before it get stopped when the next entry of the series release in stores, then it just fades away with low player count and eventually just become a desert for online multiplayer, sometimes you got weird stuff like Call of Duty Black Ops 2 to Call Of Duty Ghost where the new game is polarizing that the fans (that's debatable as I liked it a lot) decided to go back to the precedent Call Of Duty (BO2) and the devs did support it AFTER with new DLC / skins etc.
We used to have this only applying for PC games.