Earlier quoted context omitted.
I'd say that is a bit like splitting hairs, but the article does question the extent to which actual payphones and calls were actually involved..
Ponzi schemes are illegal. MLMs are legalized Ponzi schemes. The outcomes are similar but one has a veneer of legitimacy that makes it more dangerous for some people.
Both pyramid schemes and Ponzis are illegal. MLMs are illegal in many places. In the US they were successfully able to lobby their way into carving out a legal niche in the 80s. They are also the reason supplement safety is so loosely regulated in the US.