All MacBooks already have a touch surface that currently performs the functions shown in the touch bar demo. While I can see the appeal of some scenarios where it accelerates what might otherwise require lengthy finger travel on the touchpad, that doesn't come anywhere close to offsetting the loss of the function keys.
Virtually all of the MacBooks we buy we set up with Parallels or Fusion, and the F keys are absolutely necessary for Windows functionality. Having to break concentration to look at where the keys are, or their state, is a profound productivity drag.
Doubt that I'm right? Use an iPad instead of your physical keyboard for a week and let us know the results.
On a sidebar this reminds me a lot of the move to touch screens in cars, and the resulting challenges. Touch surfaces are great but not the answer to everything.