Well, considering they quit showing and quit assigning sequence numbers a few months ago, you're right they mean very little. Although, as Phil pointed out, they are still inviting everyone to configure based on when they made their reservation, so you could say the sequence number still means something. Clear as mud! ;-)
And despite what you may have read in other threads here, and despite what some folks have been told by Tesla's sales team both in stores and at the home offices, that's all the reservation number has ever meant as was stated in the Reservation Agreement. Maybe more of the sales teams should have actually read what those said before speaking to customers?