pir2 Quest pro theoretically have sufficient hardware to support (at least some sort of) hdr capability, as miniled with 500 zone full array local dimming is hdr ready, let along qled layer.
My theory is meta means quest pro is not hdr certified since they never specifically say "quest pro is not hdr capable", but mainstream media interpret it as it doesn't support hdr.
Unlike tvs and phones that mostly use dolby vision, xr2 platform like quest 2 can already decode open standard like hdr10, and skybox can play hdr10 with no significant issue (some minor glitches on my quest 2 but still watchable).
With local dimming, it will be a lot better, hope skybox team get it to work, it will be greatly appreciated.