Building an operational alpha next week is completely different from revealing it next week.
And sorry... would not abuse my contacts at TM by even asking for information about that. I'd hate to put any of them in an awkward position. So I deliberately don't ask things that they don't share publicly. It wouldn't be right. Even if they gave me bits of info, I would respect the confidentiality in which it was given and wouldn't ask followup. (And trust me, no one wants to know more than I do about the X timeline. I want the X in my garage! I want to know what the final version looks like! I want to know colors, price, options, range, battery size, how that roof rack thing will work, everything, darn it!!)
If they were going to make it an event, the Tesla way would be to announce it, let the Sig holders (or at least some) be present to see the car, have media present, etc. They'd get maximum coverage out of the event. It wouldn't be buried. It would be a buildup to get max stock bump and new reservations from the resulting stock coverage.