Tesla had planned to build 100k Model III per year leading up to the reveal.
After 400K reservations (and $400M in the bank for them), Tesla pivoted and said they would dramatically scale up their goals.
At this point, investors and reservations owners are happy with the progress Tesla is making.
If they don't make all of their aggressive goals, for sure they will make more than 100K Model III's in 2018, and they will make a goodly dent in the backlog of reservations.
Every other auto maker wishes they had the same "problem". HA!