They should have used the Anniversary to release a standalone of the Halo 3 MCC port (but fixed). Halo 3: Remastered. Xbox Play Anywhere. 1080p 60FPS on normal Xbox One, and 4K 60 on the X and PC. Customs browser, enhanced forge budget/features. Discount for MCC owners. Bundle in ODST's campaign and Firefight, too.
And if they wanted to go even further, release "The Halo Legacy Bundle" with standalone versions of HCEA, H2A, Halo 3 Remastered, Halo 4 Remastered, and Halo Reach remastered. Again, discount for MCC owners. Xbox Play Anywhere. 4K 60FPS on Xbox One X.
/A man can dream
Very disappointing in no Halo (FPS) news this E3, even if it was just a port. Hope what they show of Wars is good, though.