There isn’t much of an overlap with Bungie shooters and CoD. Destiny replaced Halo.
And Marathon is attempt to break into the f2p BR space while not being a BR. It’s hoping to carve out something new in the mainstream.
I think Deviation is the only one staffed with being able to make a CoD military shooter.
Scifi shooters are sorta a different genre…
We know that Destiny is pretty different than CoD, it's more an evolution of Halo.
We'll have to see how exactly Marathon is. What we know so far is that it's going to be a PvP extraction shooter with sci-fi setting. Yes, obviously going to be GaaS and like anything from top AAA teams is going the target the mainstream, aim to the top.
But regarding gameplay loop, feeling, game modes, features, level design, monetization, narrative etc. we don't know how it's going to be structured. We know the "PvP extraction shooter" part: you make your build customizing your character, weapon and so on and go with a team to fight enemies, collect the maximum loot possible and leave without dying to don't lose that loot. Once out you'll use that loot to craft items for your characters and weapons.
Like The Division's Dark Zone mode or Escape from Tarkov, or let's say a bit like the Souls games but in a MP shooter. But we don't know the rest of the stuff: they can take a ton of references from CoD that may end being a game that feels more like CoD than Destiny or Halo.
There are a ton of things that could get influenced by CoD (or any other popular shooter) to learn from it copying stuff people like from it in several areas and appeal their fans, like the gunplay and jumps, the weapon types, HUD, gameplay loop, leveling up system and progression system, skill tree, perks, customization, other game modes, how narrative is told, monetization system, retention features to keep you engaged coming back to the game again and again, structure of post launch content and releases, monetization system and a long etc.
I assume Bungie and the other Sony teams will take ideas and influences from all the top popular shooters of the last generation or so, will mix them and evolve the idea each one in a different direction. Each one may be pretty different but several of them can be appealing -scifi or not- to the CoD audience (which has some scifi games btw).