Ubisoft is ready to break the pattern with Assassin’s Creed Unity, and unlike past releases the game will not be delivered later on PC. Speaking in an interview with Rock Paper Shotgun producer Lesley Phord-Toy said “We’re always aiming to ship all our games on all platforms at the same time.”
“I don’t have any specific news on the PC version of Assassin’s Creed Unity, but I do know we’re planning on shipping on all three [platforms]: Xbox One, PlayStation 4, and PC. I haven’t heard any news differently than that.”
This means that you will be able to play Unity on any of the previously mentioned platforms at the same time. To be honest, my choice of platform will be made based on my friends preferences since Unity is all about four players co-op.