Since you guys at 343 now have a team that supports classic Halo games, can you guys support Halo 3? Remember how you guys recently updated Reach with removing dead playlists and adding new ones? You should do that to Halo 3, with new playlist support and run the news and updates. One example of this is the outdated bungie.net service record since it’s now retired, you can replace that with This website. An actual HD update would be nice too since it runs at 640p. You guys did it with reach, you can do it with 3 
I’m confused as to what you mean regarding the ‘HD update’. Halo Reach still runs at a sub 720p on Xbox 360, only Halo 3 received an enhanced update to 1920p for the Xbox One X.
The base game on 360 likely cannot run higher than 640p. It might be possible for a small bump in resolution on base Xbox One’s but i’m not sure it’s worth the investment for such a small, incremental increase.
I do like the idea of organising the playlists like Reach though. It’ll certainly help bring the community closer rather than having them spread out across playlists.
The Legacy Team are 343 are working on the master Chief collection, not any of the 360 games. None of the 360 games will be receiving titles updates any more.
The backwards compatibility team updated Halo 3 for the Xbox one, it’s also one of the enhanced titles for the Xbox One X