Blockchain.com is known for common bugs but if there's a hack that happened, there's no report or news about it. Those people probably have experienced the bug.
But if it's not the bug, they probably were a victim of phishing for blockchain.com. It's very common that wallet is always the subject by those phishing website makers.
sure it was not phishing. I used 2 accounts just one of them has problem with zero balance
blockchain.com send an email before ask 2FA code.phishing site can't send that email.