I don’t expect such. McChrystal most probably made the deal to get the retirement in trade for staying mum. He may have not sought it, going in to the WH, but he came out with it. I think.
I don't believe McM is a fool. Only a fool would have idly badmouthed Obama & Co. to ROLLING STONE w/o good reason. The email author here makes a good argument as to McM’s intentions.
I expect McM to hit the talk & speakers circuit soon. That will be the tell as to why he did this. If he doesn't, that will be telling, too: He WAS a blabbermouth fool.