MOS in the army, marines, and air force is "Mission Operational Specialty" - that is to say someone like a mechanic vs an infantry rifleman vs mass communications specialist (all the branches have them).
So Q could be hinting at a military-like placement/asset system moreso than "Mossad."
There are other possible abbreviations MOS qualified for - Ministry of something or other, perhaps.
It's also possible that we are confusing AJ with Alex Jones.
This is not to say that Q is ignorant of how most will interpret the post. That is how Q operates, allowing us to chase our own phantasm to find answers or additional perspectives - before the real decode crops up much later as things unfold.
There's more to it than that, but much of it is water under the bridge.