Often, after placing an order, customers want constant back and forth information from their delivery specialists. Mostly is it ready yet?...is it ready yet?...is it ready yet?
Overburdended specialists know that all this interaction is totally useless, and consumes tons of time, so they tend to go into radio silence mode. You will not hear from them until they have all their ducks in a row, and can give you a definite time to pick up your car.
Then they will spring into action to get you in to pick up your car, finalize paperwork and arrange payment.
While this is not the most warm and fuzzy way to do business, it is the most efficient, and Tesla is all about making employees as productive and profitable as possible.
Seems as though every customer has different times between order and delivery. Early days it was usually over a year wait...but wait we did.
Relax, and go about your business. Don't stress about finding out all the details in advance. They will be revealed to you as you need to know them.