There are plenty of B Billets for Marine Aviators. Some are with the Division. For instance, you may be sent to be a Forward Air Controller ( The USMC still calls winged aviators who are JTACs FACs), or a Battalion Air Officer. Other guys go to be flight school instructors, or FRS IPs, some go fly with the adversary squadrons, Some get stuck on MEU staffs, some go to strange places like the MCIOC in Quantico, or go to work in other HQ support offices (NAVAIR, Safety Center, 5 sided fun house), some do back to back fleet tours, some go to places like VMX-1 or MAWTS-1. There are a very few who might be sent to places like TBS and OCS. Some go do a tour as a Marine Officer Instructor at a Navy ROTC unit.
A lot of what happens really depends on timing and how well you can work the bro network.