Pure Speculation here, but Maybe Sony helps with Manpower and a little bit of Tech.
I hope I remember correctly, that the Pantha Rey Engine had a lot of help from Sony. Maybe it is a thank you from Capcom, so they can get the game out quicker.
Second speculation. The Fighting community is a very intense one, but I don't think too big, when you look at hardcore players. By dividing that Community it gets even smaller and the purpose of fighting and to mess each other in a Game gets lost. We know from a lot of devs that Mircosoft is very restrictive, when it comes to crossplatfrom gaming. Eventually Capcom and Sony don't want to split the Com and allow PC / Ps4 crossplat gaming, where Microsoft didn't. To not split the Community and have a common ground Cap decided to go exclusiv ?