A way to add AI to the MA to give people something to shoot at during low-number times, would be to use one of the backcountry uncapturable bases. Add AI drones at the base that will only attack friendlies. Ammo and ord at the base would only damage AI drones.
This would make a place where players could shoot AI stuff and be in the MA, so if MA action heats up they will know about it and can get involved. But those who don't want to fight AI can easily avoid it.
The AI drone base could also be open to non-subscribing players where they could fight the AI for free. They could read and post on the 'help' channel and vox on the 'range' channel, but could only read the other channels. Their 'name in lights messages' would only be visible to others within the AI base area. They could get kills, learn from veteran players who wanted to spend time at the AI base (without being cannon fodder for those vets), and see the action in the MA available to paying subscribers.