I've searched and not found any mention of this, so I don't know if this is normal or not. When at places without Munitions available I can still Reload All for a fee. Should this be possible? It seems a bit daft to me.
I found one like this last night - didn't have munitions on the menu but was able to refuel and rearm through the centre options. This was for a Military Outpost and one would expect to be able to get bombs and guns from one of those so I assumed it was actually missing from the left hand menu rather than not being blocked from the centre one.