Well, this would be sort of integration of hub in a phone (aside from that that the new chip already has built in 3 usb ports) thus a big advantage for daily driver phone that you would use as portable PC. USB3 is already supported AFAIK.
I think usability of a single port is better. With multiple ports you'd have to teach users which ports support what, like charging, display port, gadget mode, USB 3, etc, despite all ports looking the same.
At most you'd get 2 ports anyway, if you want to use USB internally for other purposes (connecting to the modem, etc.)
Power Delivery negotiations should technically allow charging from any port, but still you can go simple and use appropriate USB logo (as USB certification requires).
> At most you'd get 2 ports anyway
Two is still better than one ;-) Three is better than two ;-)