I wouldn't take my example too literally. The example was just to illustrate the basic logic for fail open and intentionally wasn't complete or detailed.

For purposes of discussing fail open, how that logic gets translated during implementation doesn't matter. Authorized(User) might be expiring tokens passed in via cookie. IsDown(AuthSystem) could just check some global flag that gets set by some watchdog service on a AuthSystem heartbeat. It could be something else. It doesn't matter because it's not relevant.

Having a direct connection to the AuthSystem or not is an implementation detail, not something that changes the idea "Netflix should fail open".