And I met a whole lot of fighter pilots in my 15 years as an A-6 BN and RF-4/F-111 WSO.
I believe your answer may not be completely accurate. The answer I am inclined to offer is the ever frustrating to all, maybe.
We all kniw the primary purpose and core priority for all FAA air traffic controllers is to, and I paraphrase, prevent collisions of any aircraft operating in the system. So why do midair collisions sometimes happen, or why do loss of separation TCAS Resolution Advisories, bark out orders to two pilots who got too close? First we must acknowledge that as fellow humans, controllers will never batt a perfect 1.000. However, more often then not, these accidents and incidents happen because the controllers' powers of prevention only go as far as those wiggling the sticks in the aircraft allow them or are capable of operating in harmony with them.
In all things in life where I'm disagreeing with someone, I always make an effort to remain cognizant of the fact that I may have missed something, or am simply wrong. It's happened many times before, and will no doubt happen again. This could very well be one of those times, so if anyone finds an obscure or blatantly obvious regulation which shows my statements to lack accuracy, please speak up. Now then...
I don't remember ever reading anything, nor could I find anything this evening which indicates that the FAA has issued any language which suggests a prohibition of ATC to provide air traffic separation services for those nonparticipating aircraft authorized to operate in active Special Use Airspace (SUA). In fact, the sections I did find which outline FAA ATC procedures meant to support exactly that, authorized nonparticipating aircraft operating inside a active SUA.
If you're looking for a flaw in my logic, the term "authorized aircraft" likely caught your attention. It would stand to reason that any aircraft which the active SUA's military airspace scheduling authority gave authorization to for entry to would be in need of FAA ATC separation services, if available. But remember, a Military Operations Area (MOA), one of the most heavily used types of SUA are not prohibited for use by FAA Regulation. The other side of that coin is that any airspace access exceptions which are explicitly & clearly outlined in FAA regulations constitute nothing short of being authorized to use the airspace.
The IFR air traffic are the ones explicitly prohibited from using airspace volumes which are contained within the established boundaries on an active MOA.
There was an incident years ago near Luke AFB where an impatient biz-jet pilot elected to descend to 17,500 MSL, cancel IFR, and proceed across the top of an active MOA which was being used for F-16 maneuvers training. As foolish or disrespectful as some may find this pilot, especially when you consider the F-16 being mandated by Air Force Orders to do so, were forced to "knock it off", or immediately pause all training until the nonparticipating aircraft cleared the MOA boundaries, the civilian pilot was absolutely within his codified rights and fully authorized to do what he was doing. The enroute ATC who had been controlling the Biz-Jet while IFR in Class-A airspace, remained with the aircraft when he canceled IFR, and provided radar services for the entire trip through the MOA.
Funny thing about "right & wrong", and how certain people will respond when they have been inconvenienced by what they perceive as someone exploiting a loophole in the rules. Case in point this day was a well known and highly respected F-16 instructor pilot who just so happened to be the flight lead with a group of students. If you've ever met a real life fighter pilot, you understand the level of ego-based bravado at play here. After telling his students to practice tactical holing procedures (totally made that last part up), our now very irritated and possibly insulted F-16 pilot made the faithful decision to go see what was so important as to waste his time, and pointed his nose in the direction his now active targeting radar showed a "bogey". It's unclear if the F-16 pilot was aware of the implications of his actions based on how his aircraft was equipped (or in this case not equipped), but i suspect he was simply trying to make a quick "Hey dude, these are your tax dollars burning away to accommodate your shortcut" point.
As the F-16 quickly closed on the now quite visually acquired bogey, you'll never guess what happened, causing this little gut check to turn into an openly argued national event! If you guessed TCAS RA "CLIMB CLIMB CLIMB!!!!" you win! The Biz-Jet, unaware of his newly formed wingman (violated both FAA regs and AF Orders), likely completely jumped through his skin at the TCAS screams, and promptly busted straight into Class A positive control airspace without clearance!
I'm sure this will reignite the debates about who was right and who was wrong. However, all the recommendations and advisories in the world published to dissuade this type of behavior by VFR pilots is all meaningless, that is if your that "letter of the law" kind of pilot. The bottom line is the F-16 pilot was the single violator of any rules or regulations, the Biz-Jet, just serf-centered.
My point in telling that story, however, was to illustrate my claims made that ATC may provide separation services to VFR traffic operating inside active MOAs.
For something a little more solid than "Some dude in the AOPA forums said....", search the FAA's JO 7110.65, and scroll down to Section 3, which in the most current version begins at page 9-3-1 of that document.
Does VFR flight following ensure separation between you and military aircraft while flying thru a MOA?
Yes, because ATC will not provide service to VFR aircraft through a MOA unless the MOA is not in use. So, if they're providing service, there are no military aircraft actively using the MOA -- even if the MOA is listed as "active" by NOTAM or scheduled hours. If it is being used, ATC will either provide vectors around it or terminate your radar service as you enter.
See FAA Order 7110.65Y, Section 9-3, for details.