Something very similar has been happening even before USB-C, actually. While USB 3.0 is backwards compatible with 2.0 for a user, it is both electronically and

Something very similar has been happening even before USB-C, actually. While USB 3.0 is backwards compatible with 2.0 for a user, it is both electronically and logically a completely different port. A USB 3.0 hub does not "upgrade" a 2.0 signal to 3.0, but it has separate hubs for each speed. In essence, they are two separate protocols sharing a single connector. This means that you could "split" a proper USB 3.0 port into separate 3.0-only port and 2.0-only port. Some USB docks use this to provide extra ports for free: something like an ethernet adapter uses 3.0, so that gives you a free 2.0 port for a keyboard.