Oldbutspry, I think you hit the nail on the head. The military has been taking a much less favorable attitude toward motorcycle in the past five years. It seems that they want to make it more and more uncomfortable for military members to own and ride motorcycles.
If you try to ship the bike along with your HHG, as well as a POV through regular auto shipping channels, you're taking the same chance I was. I hoped that the transportation office here would be oblivious (due to past experience with them being oblivious when we moved here, and not helping AT ALL when we tried to make a claim against our movers) but that didn't work because apparently they can be aware when it comes to screwing the service members, but not when helping them.
There is a disconnect between the movers and the transportation office, and between DPS and transportation, but the transpo office has the final say on what goes out.
To top it off, the transpo trolls discouraged me from even bringing a bike through commercial means because they don't think I'm even allowed to have one. I looked at the USFK regulations and they say I am allowed it, so F transpo and their useless opinions.
Anyway, I rant - the bottom line is that you may end up in a similar predicament as me, with transpo telling you that they won't ship your HHG until you remove the motorcycle. And if you're going accompanied, that may throw a monkey wrench into getting out of the US. For me, I have two weeks until I actually board a plane, so I have time to work it out.