So I've done some testing. I did remove the watch as a key in the car and re added and while it worked, as soon as the watch disconnected it has never connected back on it's own and never works again as a Key.... so
In all scenarios, the Watch itself will not work as Key, so no ability to auto unlock car, start the car, and will not show connected in the car.
I have a Pixel 8 Pro and Pixel Watch 2. If anyone else has an alternative experience with those devices I'd appreciate the comments.
Ok anyways, with Tesla (not Tessie) App as Key and Watch set up as Key, again, will never reconnect after initial pairing and will not work as a Key, won't show as connected in both Watch (Notification or Watch App), and obviously not shown as connected in the car
If the Tessie App on Phone is set up as Phone Key, the Watch will show connected (Notification and in the Watch App), but again, the watch will not be usable as a Key, will not show connected in the car. One major downside, and why I can't keep the Tessie App on my phone as a key (which I'd like to do for all the door eject capabilities), is it causes a Watch Battery Drain
I've done plenty of reboots with all devices involved.