I don't think so, really - If they wanted to do that, why not just take CPU vs. CPU out altogether like they did to 360?
My guess (and it's a complete shot in the dark) is that it has something to do with the superstar mode, and the camera switching that would have to occur if they left the demo cam in. That camera's always been used for CPU games and nothing else, so maybe introducing it into a human-controlled team (such as when your player isn't on the field) was causing them problems - like it wouldn't switch back or something when it was time for your player to take the field again.
JMO.