Spoke to my DA and have a few updates:
1. AGT production is indeed imminent, within weeks if not days since DE production is almost over.
2. Existing AGT's being produced are going to studios for test drives, though they have not opened them up for that yet (but that should happen "very soon")
3. Some AGT are also in the hands of media and I'm guessing there's an embargo on reviews that will lift right before earnings at the earliest.
With that in mind, I'm betting that VIN numbers will start getting assigned within a few days for the earliest reservation holders and their cars will barely make the end of the cutoff window they were quoted. I think we'll all be getting our cars near the end of the production windows we were quoted for a while until they're really ramping up production.