DP is by VESA, who brought you such bangers as VGA, DVI, standardised mounting systems, DDC (which enables EDID), EDID.
Although there is controversy about them not supplying the standards documentation for free, i dont believe it is licences
There's also the option of getting a DP to HDMI converter. I'm personally waiting for one that supports DP 2.0, along with VRR and HDR10+. There's a DP 1.4 one right now, but AFAIK it uses DSC to display the full 4k120, which isn't lossless.
Unfortunately unlikely to both. The displays all likely have the same controller boards with HDMI support baked in. The TVs are going to be made for people who still have cable and streaming boxes, and unless something has changed, those are all HDMI. Unless a manufacturer not in the forum decides to make a display, I don't really see anything without HDMI existing.