I'm confused, didn't the article say "A few minutes after they entered my T-Mobile number into Sakari, Lucky225 started receiving text messages that were meant for me"? T-Mobile is a normal cellular carrier here isn't it? What part of it required a VOIP line?
P.S. You can edit your old comments instead of leaving 4 different ones in the same thread.
EDIT: Looking at this 5-day-old user's history, I think it's safe to say we shouldn't take the comments at face value:
https://news.ycombinator.com/item?id=26455000