While anything is possible in this realm, I'd say it's most unlikely. What HAS been happening, slowly but surely, is that MSP is getting portables so they can access their respective county's 800 trunk system. This is happning on the Eastern Shore, and to an extent, around Central Maryland as well (Howard county comes to mind). How much this is actually used, and whether they use it just for keeping an ear on the local trunk, is another question.
73s Mike