I disagree.
As you mentioned there is the initial requirement that the app running on your PC to uses the OpenXR runtime. Currently 90% of VR games on PC don't meet this requirement. Based of my own research, I think its unreasonable to say that VAM 1.X will ever work with OXR on Oculus with these features through simple modification, it would only be possible with an upgrade to a newer unity version and Oculus SDK version. Its possible that someone could develop a separate dummy OXR runtime that might be able to run at the same time as VAM and communicates with it using a plugin but that would take a lot of work and probably come with a lot of other drawbacks that might make it not worth it at all.
We haven't seen any PCVR games that do use OpenXR implement these newer features that have been available via link for Q2 and Pro (hand+eye+face tracking, passthrough, movement SDK ect.) even if the games use the features in their standalone counterparts and that's because Meta has greatly exaggerated that these features "work for PCVR" using their own methods.
Passthrough over link had been out for over a year and was completely broken and unusable because it dropped you down to 2 FPS on the headset as soon as you activated it on top of several other issues making it difficult to getting it working at all. You can see on the Oculus forums, devs were reporting the issue and there was no help from anyone at Meta to get it working. I'm not even sure if this has been fixed yet.
Just take a look at the whole PCVR section of their forums, Meta is not providing any support for these features on PCVR to developers and is clearly not actively working on improving them. I assume this is intentional to push devs and users to make and buy the standalone apps instead where they can take the 30% cut of the revenue from their quest app store.
With all that said, I'm sure Quest 3 will still be an excellent headset for PCVR and VaM because of the new lenses, resolution and decoder. And it will still be possible to use the passthrough via VDs chroma key method although that's far from perfect MR. VD+VAM will likely never work with the dynamic occlusion or room meshing since the headset doesn't get any depth information and the passthrough feed and mesh is never sent to the PC. Its just a shame we wont get to take full advantage of a lot of this more advanced hardware the headset offers.