I've already logged into my Oculus device using Facebook. What changed?
Previously, if you connected your Oculus and Facebook accounts you could later choose to disconnect them. When you disconnected your accounts you would lose access to Facebook-powered social features and go back to having two separate accounts, one for Oculus and one for Facebook.
Now, if you merge your Oculus account and your Facebook account, you won’t be able to unmerge them. Once you merge the accounts, you’ll only be able to log into your Oculus devices with your Facebook account. You'll still have access to the same apps, games and Facebook-powered social VR features that you did before.