I'm actually surprised that they have shipped as reliably in order as they have. It would be very likely that car X would have some last minute glitch or final quality check failure that would hold up its release, with car x+1 coming off the line and ready to ship sooner. Back when the line was not moving at current rates, that was less likely.... but I would expect more out-of-order deliveries than we've seen.
That's an interesting thought. I just assumed they used a different tracking ID internally and slapped the TTC ID number on it as one of the final steps.