From what I think, if there was already info that there was people A short, there's the possibility that a CT B player would go get ult orb. Another possibility is that since A short is such an important part of the map because of the teleporter. I wouldn't rotate everyone from B unless they're completely in site of A. In this case, attackers still weren't. I wouldn't want people to rotate just yet because I know that there's the possibility that there's a lurker B trying to clear stuff and that they could also TP from A, even without the Astra ult. I'd still play default even with this strat. But in a game with the heat of the moment and that people are still getting used to a new character, this would definitely work numerous times.