So here's by detailed response https://www.twilio.com/blog/2017/07/building-a-fully-feature...

But I agree with kchr in principle. "Burner" may not mean anonymous but it's more often than not associated with anonymous and anonymity. It's the go-to perception or association if you will.

So I think kchr and I are saying the same thing: the article is using the burner/anonymity context as a little click-bait IMO and it's not a big deal but it's a valid point.