And also there is no way to know if the keys are deleted from your account, rather it doesn't show up when you log in. Think of it this way, when we delete a post on the forum, it doesn't go away. You can't see it, it doesn't show up in your history (except the increased post count) but it isn't deleted. Its still in there. I would be surprised if said key was actually deleted out of a database (not counting backups) rather just de-linked from your account, or hidden from your view.
Here's an example of an account without any keys.
I used my testing account which has been used to set up Windows 10 systems. I'm not entirely certain that Bitlocker is as automatic as they say.