The public-transport-of-the-future that makes most sense to me is the PRT.
I can’t see why FF would encourage that specifically, aside from making electricity provision to the lines more distributed and practical, but the knock-on economic effects of cheap energy might make a lot of projects far more feasible.
The key advantage to the technology is that if you build the rails as elevated monorails, they don’t interfere with subterranean infrastructure and existing road systems. The downside is that people object to monorails near their windows, but I’m sure if you made them shiny enough…