This may be the last time I comment on the Halo Master Chief Collection for a while (though I remain excited about it). A few observations:
– all of the maps from the console Halo games have been included here, but none of the maps specific to the PC games are included (the first two Halo games were also released on PC).
It’s an odd thing not to include, especially because there are suggestions that the game, when demoed, had keyboard button prompts that would revert to controller button prompts when a controller was plugged in… as if keyboard and mouse were supported. As if they planned to later release it for Windows PCs. Doing so would silence critics who had long complained that Halo 3 and later games weren’t also released for the PC.
Could a PC release be coming? If it does, would it include the PC-specific maps? My bet is that it will, and like how Halo 2 required Windows Vista (quite unnecessarily), I think it may require Windows 9. Whether the Master Chief Collection comes on PC, I wouldn’t be at all surprised to see the old PC-specific maps to be made available for the Xbox One version as downloadable content (followed by the inevitable Game Of The Year edition that includes that DLC, of course).
Writings of Mass Deduction 
There is going to be a handful of maps from the PC versions. Here is a link that shows most of the maps included.
http://www.totalxbox.com/78078/be-upstanding-for-halo-the-master-chief-collections-full-map-list/
Oh I just noticed on the article there is updates and it in fact says “A Microsoft spokesperson has told OXM that all maps from the PC versions of Halo 2 and CE are, indeed, included.”