You're very likely getting a June build or a July build that was part of the production ramp and unassigned to a buyer at the time of manufacture. The only thing I would check when taking delivery, other than the usual stuff, would be the battery state of charge. If it is near 100%, or near 0%, it could have been sitting at that state for a month or two which is bad for the longevity of the pack. (That said, it'd be foolish for the delivery center to present you the car below 20% charge or above 80% charge.)
There are thousands of these inventory 'first production' long range Model 3s scattered about the US currently, being absorbed by new buyers as the days and weeks go by.
Congratulations and enjoy your new Model 3!