Guess not or not recently
Did you just answer your own question?
As to your original question, it has been brought up more than a few times. Nothing came of it really. I believe one argument against locking friendly supplies to reds was "same supplies used for all vehicles". Does make sense, in that all sides use the same vehicles. Personally I could care less, and there have been more than a few times someone dropped sups for a Red near me, but I scooped them up instead.