It's pretty clear that Tesla is just using all of this to drive traffic to their website, with the constant reloads that people are doing to see if a VIN appears on their account page. That traffic generates ad revenue, just like all those other websites. Or, and this is totally a guess, Tesla just doesn't bother communicating because it's not their priority. Making people feel better about delays isn't much - if any - consideration for them. The vehicle will come when the vehicle comes. Telling someone the vehicle isn't coming yet might be useful to people for planning, but it doesn't serve any purpose whatsoever in Tesla's view.
Signed,
A Guy Whose Wife Drive's His Model 3 Performance to Work Everyday While He Drives a Borrowed 2001 Subaru Outback from His Neighbor to Take His Kids to Their Activities Because It's Better Than Walking ... Mostly