I got the same email on December 10th:
Thank you for your interest in Solar Roof. In April 2021, Tesla increased pricing for some Solar Roof customers. Since then, we have updated our policy for customers who signed agreements before March 27, 2021.
Since your project is already installed, we’ll review your final system to compare current contract pricing with your prior pricing. You’ll get the benefit of your old pricing, less the value of any promotions we applied to your project (like an extra Powerwall or larger solar system). If this results in a lower cost, we will send you a rebate to the address on file within the next 30 to 90 days.
Best Regards,
The Tesla Team
In August, I got a call from Tesla that they would honor my original quote. Mid-Septermber they removed my old worn out roof and the new solar roof with 2 Powerwall+ was installed. I received PTO on October 6th. I was a little disappointed with power generation until Oncor, the local Texas power delivery company, came by to reprogram my meter. Instantly, I was generating 30% more power. Unfortunately, I'm in the fall and soon winter months, so my power generation is limited (9-12 kW), but I went from ~1500 kWh to 400 in October and 170 in November. So far I'm very happy. We will see what happens next summer when hopefully I'll be generating at 20 kW. I'm also wondering if I will get some money back when Tesla finishes the review.
It has been interesting trying to optimize power so that I can fill up the Powerwalls during the day, use them to power the house overnight, while using some high power things like pool pumps during the middle of the day. I'm still not sure if I will get money back for power I generate, so I'm trying to optimize to use all the power generated.