Regardless of whether or not Rose is legally penalized in for his actions, he's likely gone from WWE now. WWE does not screw around with anything that could remotely harm their image. Needless to say, this doesn't exactly shine a good light on them.
Adam may not have actually struck his wife (though seizing her isn't too hot either), he was still arrested for domestic battery - while already serving a suspension. Vince has released stars for FAR less, plus Rose means nothing on the roster. Keeping him brings greater risk than reward at this point. Better to sever ties with him now before the case blows up into something uglier.
I also think that in this day and age, WWE would release even the biggest of stars over this kind of incident.