Sony is publishing because they made a deal with Disney to allow them to have Spiderman in the MCU in exchange to make a Spidey game exclusive to the PS4. Insomniac, a third party, is making Spiderman. Sony has nothing to do with actually MAKING the game. Disney would not go to Sony to make a Star Wars game. What would be the point? Sony would obviously want it to be exclusive. Disney would go to Insomniac, and have them make a Star Wars game, and put it on every console.