How to unlink a device in Firebase notification if a user is no longer connected

Question

I understand that Firebase can detect if a user uninstalls an app from a device and will thus mark that device UID as no longer linked and notify us when we decide to send a notification to that device.

But my question is what can i do when i user logs out or decides to log in with a different login, as far as firebase is concerned it will have 2 users that will get notifications on that device? I could be wrong and Firebase notification will notice that 2 users are connected to the same device on the same app and mark all other device UIDs as no longer linked and remove them? Is this a correct assumption?

I just want to avoid sending notifications to an app that is no longer linked to a particular user.

Can someone tell me where i can go to read more about how Firebase Notifications are actually handled?

Thanks