Through what I can see and my opinion on what parts were Activisions issues, were mainly around the production the timeline of content, the cost of this content to the consumer and microtransactions.
Activision investment and support has meant we have got far more regular content than we have ever before on Destiny and on most games (exception of Fortnite). The difficulty of that though is we have had to pay for that investment in a big way.
Season Passes are now fundamentally part of Activisions games however other companies now don't do this. Microtransactions are clearly the way to go but again should be accessible via other means (in-game currency) and if it isn't, it must be cosmetic and reasonably priced - Bungie wouldn't have put a $10 price tag on their Iron Banner, Whisper, Thunderlord, etc bundles. That's Activision.
I'll be clear in setting expectations which I think after this year we'll have to get used to - content will be slower as they have less developers. It's the quality of the content that needs to be there. That's what Forsaken was.
Until we see Anthem, which I think we're all still apprehensive about, I can't pick a game out right now that rivals the variety of content, the grouping up/social aspect, and the solid shooting that comes with a Bungie developed game.