If you own Halo: The Master Chief Collection, then it can now be updated to include Halo: Combat Evolved Anniversary. When I first read this news, I opened the game and could not see the new content, but that was fixed by opening the Xbox app and installing the update.
I haven’t had a chance to play it, but I scanned through the map list and it includes the Gearbox maps. I figured it would, since I’m pretty sure they were in the Xbox release of Anniversary Edition. They were some of the best maps for Halo PC, though. I wonder how the old mechanics, such as invincible vehicles, hold up (especially with better networking). I think I have part of my weekend planned.