Yeah it's apparent that some of these things are on parallel tracks, not fully sequential. As it looks like we're all seeing a web upgrade/change with the "confirmed" state this last week. Mostly at the same time.
The app seems to go through a couple of different status changes prior to your car getting assigned to you. First that no car is assigned to your MyTesla account. Then the email/password mismatch thing appears to be one of the states many of us have experienced as your build date approaches (I think this is a glitch as they set up your car and account). Next it will go back to saying no car assigned to your account again. Finally, about a week to 10 days out (a couple of days after you've been assigned a VIN), it will acknowledge your car and your VIN, but that you need to enable the app from within the car. Then you know you're getting close.
Caveat... there is much inconsistency with the timing of these events from one Owner to the next, as some get in on batching just right, and get a really compressed version of this, even skipping some steps. But for the majority, this has been what's transpiring since April.
No doubt they'll keep refining their processes, and keep evolving it as they go.
