You might not have insider information on the engine, but you certainly got me thinking, between what you've said and a comment from
@THECATISDEAD about OpenGL not being a standard API, I'm now wondering if the Cobra engine has been "ported" to Vulkan from OpenGL and or DirectX? From what I understand, and remember I'm an enthusiastic gamer who is primarily a mechanical engineer, not a games/software engineer, but from what I've read were cobra being rewritten to be vulkan native it would certainly be easier for frontier to release new titles to multiple platforms, so it would commercially make sense to put most if not all the eggs into that one basket.
But what I'm less clear on is how Vulkan plays with VR? As far as I can discern, and remember that I am a mechy - not a software engineer, if an HMD runtime is written in one API, but the games are written in other APIs, such as DirectX then some interoperability between Vulkan and DirectX is required. I don't know if that falls on the HMD runtimes to cover the interoperability, or if it falls on the individual games to be "bi-lingual"? If its the latter, that could be the reason the plan for Odessy doesn't feature VR?
But given that way back when at GDC 2018, Oculus announced that Oculus Go would get Vulkan support I'd imagine that will have propagated onto their rift & rift S software libraries by now, and valve software have a GitHub for Vulkan support with SteamVR/OpenVR I genuinely don't think that implementing VR in a Vulkan version of the Cobra engine would be an insurmountable challenge?
This is not an authoritative post, this is me doing some tinfoiling and engaging in trying to see things WRT Odessy +/- VR from frontiers point of view, but I think it has presented an interesting possible insight as to why Odessy may not get VR support.