I guess there's an element of "damned if they do, damned if they don't" about it. They could give you an estimated delivery date every two weeks, but we all know from experience that it isn't worth anything. Or, they could wait till there's something worth telling you, in which case you feel neglected.
I ordered through a lease company who did update me regularly, but this just led to frustration as the expected delivery date moved all over the place (see my previous posts). Eventually they told me that they would provide no further updates until they had a build date from Lexus, and maybe that's the best way to do it?