Im not going through hundreds of weekly updates because you apparently weren't into gaming back then if you have no idea about how bad the MCC was. It wasn't even playable 100 days after release (there was a reddit post title along the lines of Day 100: still broken).

No AAA game has had months go by and still be completely unplayable. Even after a year, you could now find games but they are always uneven 3v5, 2v6, never 4v4. And now years later, many features are still missing, some issues in some versions of Halo remains. All this happened to what was supposed to be a major console seller. The game flopped and many veteran Halo fans from Halo 1/2 were left with hate towards 343i and vouched to never buy a Halo game again.

It was a huge deal at the time and 343i just brushed it under the rug like it didn't happen hoping the community would forget (or turnover). They stopped talking about the MCC and only talked about Halo 5 in their updates, despite many fans pushing for info on fixes. Obviously, they weren't going to say why they gave Halo 5's DLC for free, but it was obvious if you were following the company at that time that they were trying to do something positive because many were starting to view 343i very negatively.