The article sounds like this requires you to sumbmit a cell number to Gmail. (In fact, I think merely registering an account nowadays requires a number, but I'm not sure about that.) If you think that's the only way to get 2-factor authentication working, you're wrong. If you think there is nothing wrong with your email provider demanding info like cell phone numbers, you're wrong again.
I don't think there is anything wrong with an email provider asking me for my cell number to send me text messages, how else would they send them? In addition, a cell phone number is NOT required to create a Google account. Sure they ask (and gender is apparently required, I just made an account), but if you leave it blank, they won't complain.
How can this be implemented without using a phone number? Well, the article actually contains one way - pre-shared secret codes that you print out beforehand. There are many others.