More than that. Their first move was cutting trading fees, which made FTT worthless (it was useful before for traders to use to reduce their trading fees but with free trading on Binance that became worthless). After Binance made FTT worthless, they then started to sell theirs off (knowing that it's worthless because it's a race to low/free fees). A bank run would have been inevitable anyway as large traders would rationally sell their FTT and move over to Binance for free trading (they pay zero fees and can pocket the money they can get from their FTT). CZ's tweet just accelerated things.