That is, if Elon Musk changes his stance on bitcoin specially about bitcoin mining. Otherwise, this is just moot meeting and I don't see it will have a drastic impact on the market. Jack Dorsey though is a willing participant here. But if Elon Musk insist that bitcoin is harmful to the environment then there's nothing that Jack can do to sway his belief.
But probably more crypto enthusiast are going to tune in and wanted to hear Elon Musk. Specially when he started spewing things that he doesn't have knowledge (bitcoin mining).