There shouldn't be any doubts, it's definetly will not be 2023 and its not the point. Everytime Elon mentions date, media just takes it for granted and repeats itself everytime the deadline is missed. In reality, if you have only broad understanding what is needed to be done and you can only make assumptions about how long it will take, you still need to target some specific dates and try to stick to them even if more often then not, you will miss these deadlines. In this case its the date if everything would go to the plan perfectly. But we are not living in the perfect world and who knows that difficulties could accur or how long they could take. How you can incorporate these in your predictions? Its very difficult to properly predict big projects and this type of projects are in scale which is even more insanely difficult.