As should be clear from reading this thread(and any of the other waiting rooms) we have no inside information on why/how Tesla does anything.
The "understanding" is that they are trying to get as many cars into buyers hands by the end of quarter.
This means that they sent almost all production in October/Early November on ships(Europe/Asia) since they have the travel time, etc.
Once they turned to US, they build in groups, so similar models(LR,SR,SR+,Perf, Steatlth) are built at once. As they start planning the last production for the quarter, they are prioritizing East to West deliveries(once again transit time) and they seem to be building a few extra of each model for the areas to have a few available for a last minute buyer(seen by the guy who got his car on the East Coast within 6 days. I can not believe there is any WAY that they BUILT that car specifically for him and got it through production, QA, transit and delivery in that time frame. It was either a reject from someone else, or an "inventory car". The Stealths seem to be a similar example.)
Since they can get a car to us in the bay area within hours to days, we get the short end of the stick, Northern and Southern California seem to be treated similarly.
I expect that they will be able to get those cars to people who purchase by 12/8...but whether their delivery time works for peoples holiday plans is a different story.
I imagine we will hear more stories of people picking up a car last minute and gets it by 12/31 even if they did not have an order before then.
Sorry for the wall of text.
TLDR: Anyone US who ordered in Sept/Oct were "ignored" until production/shipments for US started in Nov. Any order since then, they are working through and expect to clear all current orders by the last 2 weeks of Dec, and any cars after that will be for people ordering between now and 12/8(and a few inventory cars) which will be available for last minute buyers