User Profile

I am integrating with Sign In with Apple, but I've got confused by the doc. It says here and here that the user identifier is team-scoped and is the same across all the apps in the development team associated with my Apple Developer account. Now my questions are as follow: What if I leave the team? Will my app still get the old user identifier? Likewise, what if I joined a team? Does it mean that apps developed by different developers get the same user identifier as long as these developers are in the same team? How does it work if I join multiple teams?