They would have to limit the number of allowed spectators per room, that is the only thing i can say for certain. I don't think its going to happen though with all the extra coding that would need to be done so spectating wouldn't become a buggy mess. I'm pretty sure most of the custom code doesn't take into account a regular player spectating since they aren't considered the same as a hidden staff member in the code. So unfortunately its not as simple as flipping a switch and would take quite some time.
