I agree with the conclusion that the insideEV numbers are not necessarily an indication that 1000/week target by end of January wasn't reached. But one thing to keep in mind that there is something different between S/X and 3 wrt in transit. The former pipeline is much, much longer due to international deliveries. All else equal I would expect the 3 pipeline to be smaller. I think not everything else is equal though. Many service centers need to familiarize themselves with Model 3 before they can deliver in numbers leading to local build ups (there are a lot of reports of centers with up to a dozen cars waiting).
I agree with all that, and have also seen many reports of local build ups as Tesla smooths out the delivery process ("just in time" delivery infrastructure/personnel/training to minimize OpEx -- you should like that ).
As noted in my posts above, probably the biggest factor is that Tesla optimizes quarter-end deliveries to some extent but does not try to optimize month end deliveries. Every indication is that is the case with Model 3 deliveries with many orders outside CA in process at the end of the month, so I expect there are a larger number of cars in the delivery pipeline relative to production than at the end of a typical quarter.