Everyone discounts before they launch a new product. You don't need to follow Tesla to know a new product is eminent when you walk into a show room and they knock $10k of the price because you look pretty or walk nicely. Big deals and big discounts with serious need are always informative to the buyer.

Plus people but cars when then want cars, some will always lament they could have waited a bit, but most I expect will be happy to own a Tesla that was (and is) amazing just a few days ago.

I don't think making an good buying decision should need to take subliminal cues into account, like someone predicting a storm by a sudden shift in wind behavior, and forcing your customer base into this buying paradigm is a huge risk for resentment and product dissatisfaction.

Car manufacturers generally telegraph their intentions for introducing new technologies in advance of actually unveiling the new models. People who buy a new 2016 Honda Accord generally can find out exactly what's going to be in the 2017 model just by googling around a little. Not the case with Tesla.

At the end of the day however, it is not Tesla's responsibility nor in their best interest to educate their customers to make intelligent purchasing decisions.

If you want change in this regard, it's not going to come from Tesla.

It can lead to buyer hesitance, which is a problem. Why buy now when the car can suddenly become better? Without any understanding of when it would get better, or how much, the fear of the regret can be substantial.

Well if BMW communicate upcoming changes much better than Tesla do, maybe I'll buy BMW instead. Shrug.

depends what kind of brand they are trying to develop. with cars many people are still traditionalists and stick to what they were happy with.

It doesn't help that Tesla tends to have long delays for cars.

For instance, let's say I pre-ordered a Model 3 now. But I won't get it the first half of 2019. And then a month later, Tesla announces Model 3 with Autopilot 2.5 hardware or whatever, holographic HUD, and so on. And that new car will ship within 2 months. Then I'd feel pretty screwed by Tesla...

You don't understand the Tesla order process. People waiting in line for Model 3 have not picked the exact details of their cars -- they do that right before the car is produced. If new stuff is announced, it's immediately available. So the only people who are pissed are those whose cars are in the assembly line.

In short, the delay between reservation and receiving the car is not an issue.

If they announced upgrades and that the new car was shipping in 2 months you would be at whatever current build was being deliver (sans any cosmetic changes they may request your input on). If the manufacturing lines are updated to add features as a baseline after you order but before your build, you will get whatever they are.