Pre orders wouldn't be possible until announcement, and since this would be an update to an existing model, it will probably be available upon announcement.
If anything, I could see this shutdown providing an opportunity to make any adjustments to the line necessary for Plaid drivetrain, updated charging, battery architecture (ie. temp management), and updated interior happen more quickly.
I also believe Elon suggested Plaid would ready by fall, but I think that like the Y, it will come sooner. I imagine a performance model would be more appealing to potential buyers in a lead up to summer months, rather than closer to Winter