CZ admitted in one of his Tweets that Bitcoin's ledger is the most immutable ledger on the planet. He understands it now.

If he really believed that, he wouldn't even think about bringing it up. Could it be ignorance? It could be, but you would expect him to know how Bitcoin works considering that it is what his exchange depends on the most. He also needs BTC to dump his BNB stash on people and accumulate as much BTC as possible before his ponzi coin and exchange go bust.
Now is a good time for him to tell us to use his DEX.
It's not a DEX. It's a centralized shithole to pump his BNB ponzi coin.