@red river hog I'm unaware of any N. savannula in US zoos but there are a few holders of N. annulifera. If there are any of the former present I would expect them to have gone largely unnoticed given they were split from Naja melanoleuca very recently.
That said, I have no idea what any "forest cobras" we have kicking around actually are post-split.
@ThylacineAlive Late reply, but are all species labelled as Egyptian Cobras with bands actually Naja annulifera? Staten Islands are also annulifera (sign lists them as an Egyptian subspecies). I wonder how common actual Egyptian Cobras are then? Central Florida is the only zoo I've been to with a non-banded individual.
@SusScrofa most "Egyptians" are actually annulifera, yes. Central Florida has true Egyptian I do believe. I'm not sure how common either are but I do think true Egyptians are rather rarer.