Why do you think the USMC is not getting the Bravo model?
From recent Flight magazine:
The US Marine Corps will stand up its first operational Lockheed Martin F-35B squadron this November if everything goes according to plan, a senior service official says. Prior to that, the USMC hopes to formally start training new F-35B pilots in October at Eglin AFB, Florida.
"VMFA-121 will now be the first squadron to stand-up in Yuma, [Arizona]," the senior official says. "They will stand down as an F/A-18D squadron in July once they return from deployment to Japan."