Dolby Vision is a proprietary format. So unless Dolby develops something (highly doubtful) then it's unlikely anything will be developed. It would be incredibly complex, and almost certainly lead to legal action from Dolby.
Yes, but that support is limited to playback. All it does is pass the Dolby Vision metadata to the output, which means you need a Dolby Vision display to actually use it.
Nope. You don’t need a DV compatible display with the latest MPV. Their latest gpu-next renderer can tonemap DV to SDR or HDR so as you can watch it on an old display.