Vanguard: is the middle rack a permanent change?

I don't know what the middle rack is. I'm not sure what they're referencing. I do know that the Vanguard currently has its own missile racks that are size 2 and are lovely. They also fit on an Avenger and a 325A, and you can actually load up a 325A with them and have the ability to fire 8 missiles at once, which makes the 325A pretty devastating right now. Those probably aren't the final racks. I was talking to John Crewe about it. So they'll probably be changed at some point. That's why they're just Aegis Quad Rack, and they'll have a fancy definitive name. But while they're in there, you can have some fun.

This may have been the very specific answer to their question, now that we think about it.