You don't order a new computer when there is a presser scheduled and rumors of a new, much faster processor. You push a few weeks if your situation allows - however, if your computer died, you have to replace it.
I saw this as a similar situation. Wise move is to push a couple weeks - which is what my wife and I did. Held of on ordering close to 3 weeks. Delivery day happened to be today, Battery Day, we pushed back one more day. Will pick up tomorrow. I thought the chances of something quickly changing was low.. but how much would I regret if something big was coming a few weeks or even few months out.
That said. What did we learn.
1. New Battery Tech coming 1-5 years out.
2. New chassis design making battery pack a structural component - prolly 1-5 years out.
3. Front and rear single castings are coming. No ETA. We know they are currently testing the casting machine - we don't know if there are problems. We don't know if the single cast unit will perform adequately in it's current form. We don't know how much testing will need to happen before they enter production. We can speculate about some structural rigidity.. but really, it may just help on production. In fact, it's entirely possible the single cast may be worse for consumers in that, like the frames of old, if it gets bent or broken in moderate crash, it may be very, very expensive to repair.
So. While I think it was wise to push purchase if your situation allowed; I don't see anything real info that would justify waiting further. There will be constant and regular incremental advances for many years (we hope).
My 2c.