Retired military officers who draw pay remain subject to the Uniform Code of Military Justice (UCMJ), particularly Articles 133 (conduct unbecoming an officer) and 134 (general article, which can include seditious conduct).
Seems more like a military thing base on conflict of interest. Why would they pay out $6k/mo to someone undermining them? He's free to say W/e the hell he wants on his own dime.
Contrary to popular belief a lot of the younger recruits that are just joining the services these days are a little bit smarter than some people may think.
Because of the actions of senator Kelly, you going to get quite a few low ranking individuals in the military looking at their direct superiors and asking whether or not what they're about to do is legal, and then based on the answer they get refusing to do what they're ordered to do,
Politicians think that the military is about grunts doing what they're told no matter how bad the orders are. It's not. The day-to-day actions of the military are about brotherhood and trust first and foremost. If those people that are performing this shit don't trust each other this is all going to fall apart and fast.