MSOCs and FMTU may be Marines, but they are SOCOM forces. I doubt that they will operate in direct support of, or with, other USMC forces. There may be bleed over in skills/knowledge when FMTU Marines go back to USMC operating forces, but FMTU will be built and trained to fulfill SOCOM missions. That is good for SOCOM and generally good for the nation, but, bottom-line, it is force structure that the Marine Corps no longer owns.
An excellent point I had actually meant to add.