This year has seen a lot of change in the technology used in monitors, with 4K, adaptive refresh rates above 120Hz and HDR becoming common features. These new features did not exist when DisplayID first replaced the veteran Extended Display Identification Data and so there were no overarching standards governing their implementation. We have also seen the advent of consumer VR and AR which also lacks a standard for companies to follow.
The new DisplayID 2.0 standard is specifically for these new devices, with the previous standards remaining to govern the compatibility of legacy products. The new standard describes how manufacturers can use the modular data block design to send clear information about their devices capabilities to the hardware powering the display. If followed this will greatly enhance the compatibility of variable refresh rate technology, screens with 4K or higher resolution and wearable displays.
This will help you avoid experiencing the frustrations early adopters have experienced and will hopefully restore displays to a state where they simply work when plugged into a compatible GPU. We won't see huge jumps in performance but this will certainly help in the development of 4K displays with high refresh rates, once the power of our GPUs catches up.