The general consensus in that thread is that, while the Vision Pro can play “flat” porn videos on sites like PornHub, there is currently not an easy way to play 180 degree side-by-side videos on the Vision Pro, which is how most commercial VR porn is filmed.
There is a Star Trek app that plays SBS 3D videos, so it’s only a matter of time before someone puts out a dedicated app for it.
This proprietary tool can already convert SBS to MV-HEVC. I imagine we will see support come to ffmpeg and/or x265 in the next year or so, if it’s not already being worked on. MV-HEVC is very similar to the MVC extension to AVC that was used for 3D blu-rays, so it’s not particularly exotic.