Respawn has the rights to do what they want going forward. EA had control of this one since they funded Respawn.
EA could also change their minds on the first title (pretty sure there is a loophole).
EA's is all about the money. They've shown this time and time again.....watch them nikkaz.
But at a minimum, the Titanfall sequels will be on the 4. Get an Xbone or PC to play the first one.