It has been revealed in Geff’s final hour of titanfall, that Sony had multiple opportunities to get the game on their platform but failed to due so, and Microsoft funded the rest of the games development.
There are couple different reasons why the game ended up not coming to the PlayStation platform. Essentially, Microsoft was talking with them about Durango very early on and courting them to move Titanfall over to that. They asked Sony if they could talk to them about the next Playstation, but Sony constantly said they weren’t ready to discuss. It even mentions Sony were willing to help Respawn to get a Vita version of the game. It mentions that they essentially pleaded with Sony, saying “Listen, things are about to be locked in behind the scenes. If you want this, please talk to us”, which Sony again declined.