https://blogs.halowaypoint.com/en-us/blogs/headlines/posts/halo-e3-2014-wallpapers-and-more

:Previously, we’d told you Tombstone and Desolation were not included, but the good news is
:that those are going to be in the game along with their counterparts, Hang ‘Em High and Derelict.
:Basically, every single multiplayer map from Halo 1-4 is included in Halo: The Master Chief Collection.

I was also told on twitter by Tashi that all the Halo PC maps and Halo 2 Vista maps are in as well.

https://twitter.com/Tashi343i/status/476560004212744193

So maybe it was 93 maps, but now it's 99? They could clear this up by just posting all the maps as you've done above.