They're having difficulty finding a proper release timeline for the game since SFV and TEKKEN 7 are around the corner.
http://www.siliconera.com/2015/07/12/tekken-x-street-fighter-is-well-into-development-says-harada/
http://www.siliconera.com/2015/07/12/tekken-x-street-fighter-is-well-into-development-says-harada/