If they know and understand that they should not entertain the idea of sending their private keys or passphrases to any site, they will have the idea that there is a possibility of phishing the most important thing here is knowledge and understanding the basic and cardinal rule of Cryptocurrency and that is not giving your private keys to any third party site the cardinal rule never change so always have suspicion when something is not right.
It's not uncommon to hear bad news from metamatask about phishing, even though it's not from the official party, but scammers always have a way to shock the public, including asking for private keys or other types.
It's true that what's important about a basic understanding of cryptocurrency is not to provide a private key because that's entirely our right to know, not other people or relatives.
Usually, phishing emails comes from a fake address, but in this case, this email came from the original email which may have caused people to believe in it. Not everyone will go on the internet and search if MetaMask requires KYC or not.
Likewise, I often see messages from fake emails with many variations, but this time it was indeed a stir from the namecheap support email that made big news, but at least by getting into the news in several big articles one can see that it was not all from metamask or Namecheap for denying it.