There is no way it can attract new viewers by any means. If I want to watch something on YouTube, I definitely not gonna click on some random dude commenting about something I can't even see. And even as a fan, such concept sounds stupid.

And I would argue it hurts ppv rather than brings. You listen to commentary, you learn precise details of what happens, you go through the tension of the unknown and get all your answers. After that buying ppv is less relevant, since you already practically lived through the fights.

You can at most argue that live commentary doesn't hurt ppv purchases, but there is just no chance for it somehow helping ppv.