A use case for computers, especially HTPCs, is to use display port for your monitor and connect your GPU to an AVR using HDMI.
The problem with this is that you get a phantom HDMI monitor because of the way HDMI works.
If AMD can add the option to keep the HDMI audio but suppress actually turning it into a separate screen that Windows sees, it would be a major advantage for AMD, because Nvidia isn't delivering on this.