I got the email today at 1:33pm also (Houston time). I agree its poorly worded. It says
With continued streamlining of our manufacturing process and the discontinuation of the Long Range Rear-Wheel Drive Model 3...
but they are only discontinuing it for the white interior. They still are building the LR RWD with black interior. I called the sales desk at Tesla (I have no delivery advisor yet) and after 33 minutes on hold I finally got an operator. I asked her if the LR RWD with white interior would be returned to availability once the new year starts and she said they were told the Tesla semi truck needed the batteries so the MR battery would probably continue to replace the LR battery next year also. I really wanted the LR battery, but I could get by with the MR battery and I would be able to get the full $7500 tax credit. So I told her to switch me to the MR battery. She put me on hold to find a "Inside Delivery Advisor" and then came back and said my records show I don't have one of those yet. It was too late (9pm Pacific time) and all the advisors had already gone home. So I have to call back tomorrow (same sales dept number) and they will connect me to a delivery advisor to make the change.
I have a feeling that the MR battery is going to be very temporary to just maximize the number of Model 3's Tesla sells before the end of the year so the stock holders will be happy. I get that. So I could wait and probably get a LR RWD with white interior in January. But I would lose $3750 in tax credits and the tax credit I would get wouldn't be available for 15 months (March 2020).
There are two more lines of cell production that Panasonic is installing at the Gigafactory by the end of this quarter so battery cells won't be in short supply anymore. Even with the semi truck. But I could be wrong, so that is why I decided to choose the least of all evils and go with the MR RWD with white interior.