Sorry but this is exaggarated. Yes, it is centralized in the validator selection phase. Their consensus is already POSA ( Proof Of Staked Authority). In that consensus, each candidate validator should have some amount of the network token (BNB) and an authority (Binance) should accept it as a validator. This was not a hidden secret. However, there are independent reputable validators such Coinbase (Binance rival), MathWallet, Certik, Ankr, Figment, NodeReal. Possibly some of the rest are also independent but I don’t know their reputations. So there are some type of check-and-balances.
So how they suspended Bsc chain? Just tell all 21 validators stop validating transactions?
Acc. to their story in Twitter, yes
Decentralized chains are not designed to be stopped, but by contacting community validators one by one, we were able to stop the incident from spreading. It was not that easy as BNB Smart Chain has 26 active validators at present and 44 in total in different time zones. This delayed closure, but we were able to minimize the loss.