About the stuff that's based on Elon's assertions:
First, yes, he is often wrong on timelines. Nobody doubts that. By the way, for other car companies (even Waymo!) who claim they'll have X milestone by Y date, everyone is understanding, since timelines slip. For Tesla, apparently it's a capital crime to say "I think we'll have it by then" and not have it. But your original points were not about timelines.
As for the miles they have registered with the DMV, Tesla's self-driving programme does not follow the same path as others. They are progressing from level 2 upwards, and deploying improvements to their fleet of cars in production. Other companies are working with tiny fleets and aiming directly at level 4+. So basically, you're looking in the wrong place. But even so, Elon's latest prediction is that they'll have "feature completeness" by end of year, and then they'll start working on regulatory approval. So I assume that's when you'll start seeing miles there, and you will very likely see lots of them, all at once.