Above answers are correct as confirmed by Matt a while back. You can squadron docked Drakh ships up before the game, and when they launch must either stay within squadron range of the mothership while the rest of the squadron is launched, or leave squadron.
An interesting facet, only ships that are activated can leave squadron, so if you launch 3 out of 4 you can't actually say "these 3 are going to go off as a squadron and the one that is still docked drops squadron". For that to happen you would need to activate the one that is still docked, which is not possible. So if you decide to move off the first 3 without waiting for the 4th, then they must all leave the squadron.