That is a good point, however, how do we even know if there is anything better in the next couple of months. It is all rumors and speculation. Let say the new feature is the the single piece casting, who is to say there is even a noticeable benefit to the owner. You don't actually see it.
I think everyone is assuming there will be something better in a month or so, but who knows. Why not wait 2 months, or 3 months, or 6 months, there is potentially something better. And in the end you still don't have a Tesla
Just to get 2021 model instead 2020 is the reason to wait.
Nothing else.
Imagine selling your car in 3 years from now and someone will say " good thing its not 2020,first year of production with many problems".