Apple could still offer different SKUs of MacMini with, e.g., different number of TB3 ports.
A cheap one with just one TB3 port (to be plugged into a display that then offered USB3 etc.pp.), a middle tier one with two TB3 ports and a high-end one with three TB3 ports, capable of doing 3x4k (which Kaby Lake does, AFAIK). If they only offer TB3 (and audio), these should be cheap enough to make and still offer an attractive enough product to generate a nice margin for Apple. Even though they don't really sell displays anymore.
That said, does anybody know of any non-Apple Kaby Lake desktop that offers 3xTB3?
I have no interest at all in 3d stuff. I just need desktop real-estate for my terminal-windows and Sublime ;-)