I think this is Elon playing with us/media. You couldn't buy an ad campaign charged as this one. I know you can pick this apart but it's my not so strong opinion.
A summation of what we know (for my explanation) is the leaked information of the EPA info and someone at the show showing us the screen of an Austin built Standard MY. Too much conspiracy theory?
How convenient that the Big Secret Model Y had the power on, sitting in the middle of the floor with a stranger taking video of the screen. No flags? I think it's all to make us go astray, talk about it until the sun comes up, get the word out that everyone wants one of these and all the innovations. This plant could build the Hertz order in 3 months. No one can foretell but I believe same size structural battery packs with different configurations could be replaced on the line without much of an interruption. Remember, Elon said it's the factory that's the innovation.