I’ve seen in some place (but can’t remember where) that it could/will be possible to maintain a xr session when loading a new page (instead of exiting then entering session). Thus the loading of a different webpage could be invisible on Oculus Quest 2 for example.
I’d be curious too to learn if this is possible. What you’re describing sounds like a security issue. I think all browsers are moving away from things like these that happen “behind the scenes” to prevent bad actors from redirecting users without their knowledge.