Not very clear. Did the article say your number can be given to a hacker without your involvement?
Yes. You will find out that someone took your SIM card when your phone reads “No serivce”.
That’s right. Using text message as the second factor of the authentication has proved to be insecure. There are a number of ways things can go wrong. This is only one of them: SIM swap scam - Wikipedia.
So much for double authentication. Other than phone, your iOS devices and Mac would receive the secret code for change so you would know some jokers want to change your account.
I realize apple no longer use message authentication. It uses secured unit of the iPhone so changing sim won’t work 
What does that mean? We iPhone users don’t need to worry about this scam?
Another phone scam.
Ben Shapiro?