Question about gates.

[Voodoomancer]

Does the AI have to have a connection to a planet to reinforce?

As I understand it, AI reinforcements come from outside the galaxy, presumably through the exo-galactic wormholes on the home planets.
So If I were to, say, destroy a gate in a chokepoint system for the AI homeworld (one that you have to go through to get to or from it), will I have cut the AI access to reinforcements? Or will the AI send them through the wormholes? Or use the other AI's exo-gal. 'hole?
Or does it have no affect at all?
 

[x4000]

No effect at all.  Warp gates are used for offensive raids only, slingshotting their ships from outside the galaxy into adjacent planets.   Other various ships (including command stations) are Reinforcement-type Warp Gates, which basically are just beacons for the ships outside the galaxy to warp to.  There is no way to cut off reinforcements to an AI planet short of destroying all of the Reinforcement-type warp gates on it, which includes their command station.  The wiki has more information on reinforcements, if you are curious.