So will USB-D be announced before then?
USB-C is highly extensible (some would say way too much), I doubt we will need to make a connector that is physically incompatible anytime soon (although I'm sure the standard will be upgraded for more speed/uses)
Didn't USB-C already do that to itself? I suppose that depends on how narrow the definition of "physically incompatible" is. But IIRC you can't buy a perfect do-everything USB-C cable today, because some USB-C use cases are flat out incompatible with others.