Oculus Integration or XR?

I have been creating a game which I am hoping to get onto the Quest 2 in the future. Whilst everything has been running smoothly using the XR plugins I was recently told that for games to be published within Oculus the Integration kit needs to be used and XR is not supported on a official Oculus title.

Can anybody shed some light on this please? 

I have spent soo much time learning XR and C# to support XR functions to now be told that it could be effectively useless if the publishing platform I'm looking at is Oculus.