Late embargo's can be a problem, *BUT* I don't think Titanfall will review badly... in fact the press have been so positive I cannot see it scoring that badly at all (7's will be the lowest, but most will probably be in the 9's). I mean if they reviewed it badly after all their hype, that wouldn't be good at all... so no I don't see this as a problem.
I suspect with it being online only and them not really detailing what the game is all about content wise, I suspect they are just trying to keep it under wraps for as long as possible.