Apple doesn’t like the digital audio output on its devices very much these days. They removed it from the Apple TV 4, and now have ditched it from the new MacBook Pro (with or without the Touch Bar). Here’s what the specs show:
This is also the case with the MacBook and the MacBook Air, but previous MacBook Pros have included the digital audio output. Because it’s a “pro” feature, of course. If you do work with audio and depend on that output, consider your options. You may be able to use USB, if your audio peripheral supports it.