It doesn't work that way, besides, I can't imagine anyone wanting to keep their big, beat up old M9's.
It's kinda comical to me, the "gunny" reaction to this. A week before the announcement, an M9 thread would contain a lot of bashing. After this announcement, all we hear about is how much of a waste of $ it is and how the M9's are just fine etc. The M9 was fine, they are reliable and get the job done. They are also overly large (hard for smaller hands to grip/operate), heavy, and have that hideous slide-mounted safety/decocker and are getting quite long in the tooth. They aren't going to be missed by anyone I've ever met in my Army career.