I've been seeing a tonne of VR permission requests lately, and always on the most unassuming sites. Never seems like there's actually any VR content available.
Heck, I haven't even had my VR headset plugged in since Christmas. Does the browser cache that it existed, know there's drivers or some such on your system, or would it be asking regardless?
Apparently Vimeo can be played inside the VR headset? I am not sure but I get this message everytime I open any website with an embedded Vimeo player.