Sorry I reply so late, I missed your comment. I play MCC almost on a daily basis.
I have 2.783 hours played in MCC (Sad, I know), recently completed LASO on all games, been onyx in H5, and I was lvl 50 back in the H3 days.
I know what I am talking about,
Here is my service record.
I have to be honest. I have no clue where Bungie would have taken Halo after Reach. At least 343 tried to continue Halo on a path where the wind was set by Bungie.