It's more so when they joined Activision. There was a lot of issues that lead to many Halo devs quitting because the vision Activision had didn't match what the people at Bungie wanted including a complete story change.

Not really, when they were with Activision we didn't get content from D1 and also the dlc's were cheaper. As soon as Activision left Bungie, Bungie instantly brought back the moon as their next dlc. Also the 4 seasonal activities were pretty much the exact same. Season 1 and 2 were that same and Season 3 and 4 were the same. After that Bungie nuked the game with their Sunset. Then we got pretty much all of D1. Hate Activision all you want but at least we got some more original content and they were a lot cheaper as well.

Except the entire game was changed by Activision and this lead to many of the devs quitting and being replaced thats the issue. Your issue is current bungie which only exists thanks to the Activision Bungie deal.