I know we’re all in a frenzy here but this is what Kojima said in a famitsu interview, quote taken from dual shockers:
“ As far as games go, Kojima Productions "is planning to work on multiple game projects, one of which would be a 'big' game". But Kojima is planning on making some smaller games, too, including episodic and digital-only titles. And funnily enough, despite the babies in snow globes, both Kojima and Shinkawa believe that Death Stranding may be "considered to a be a 'weird' game" but it's actually "very similar to what they've done in the past and they personally don't think it's weird". In fact, they want to make their games even weirder. Stay weird, Kojima. ”-Dual shockers.
It sounds like he has a few games he’s working on. Maybe this game is a smaller project while the bigger one, (death stranding 2?) takes awhile to get up and running. MS gets their Kojima game, albeit a smaller episodic game, Sony gets their big game. That sounds pretty reasonable no? Remember e3 2013 where ms showed of mgs5 for the first time and lied that it was exclusive?