Worth posting Bloomberg's Tesla Model 3 Tracker, which contains a model attempting to independently estimate production, as well as background info about Tesla's past projections: https://www.bloomberg.com/graphics/2018-tesla-tracker/
I think most people shouldn't take this tracker seriously as it was wildly off most of the time and was often manually adjusted.
Today's announcement says 9,766 M3s were produced in Q1: 9766 + 2686, i.e. 12452.
They don't seem that far off?