I too am undecided on this and would like to hear Tesla's rationale.
I do think that if it comes down to being concerned how people might interpret the results, then that is a position of weakness. It's essentially an admission than Tesla's results cannot stand to scrutiny. So, I would tend to see it as an expression of confidence if Tesla were to be more transparent. From what I hear, Tesla has nothing to be ashamed of. They've got a substantial back order and are busy trying to fill it. Even during the fires, I'm pretty sure they kept the factory humming a full speed with a sufficiently large queue of eager customers. I don't think we want to report orders, but actual sales should not be a problem. Basically you have the factory pumping out so many cars per week. Depending on where those cars get delivered and how many become service cars at stores and service centers, you've got flow into the market. Adjunct information such as the average time in transit to various markets can easily account for the ebb and flow of deliveries. I'm sure several people on TMC and elsewhere would quickly figure out how this all works and would be able to explain how weekly production is transformed into monthly deliveries. This data could become a really powerful tool for proponents of Tesla.
Tesla has a good story and strong numbers to tell it. Tesla is not afraid to open its patents. Why should it be afraid to open its sales reports? If Tesla wants to spur competitors to make Tesla-grade electric vehicles, why not let those competitors keep score and see how Tesla is cracking open an attractive market? If Tesla wants to break free from the tyrany of trying to hit quarterly sales numbers, why not dispel the suspense by routine monthly, even daily or weekly reporting? That is, the time and attention analysts and investors place on trying to anticipate quarterly numbers might be better spent focussing on longer term strategic issues. If you already know results from the first two months of the quarter, the concern about the third month will not be so great. So analysts will do a better job of predicting quarterly earnings and attention will shift to more important questions. As a long-term investor I would rather not have to spend any time guessing at what next quarter's deliveries will be because that is not the most important thing that Tesla is doing. So openness and transparency have the potential to draw more attention to the things that matter most and lead the transformation of the auto industry. Tesla has a wonderful story to tell. Why not open source reporting?