The Model 3 was a completely different market segment from the Model S, so they could hype the Model 3 to the moon without impacting Model S orders (atleast for a time).
With the Model Y, they can't brag how much better it is than the Model 3 because it will cause prospective Model 3 buyers to wait for the Model Y, rather than buying a Model 3 and Tesla needs Model 3 cash flow to fund the Y program.
Missing production deadlines and Targets is also common for all other existing OEMs as they keep promising X EV model will be introduced in 2018, err 2019, err 2020, err 2021 etc
Like it or not Tesla is the only OEM actually deploying autonomous tech in mass in a consumer vehicle.
NOA is basically a Level 2 system which can do all highway driving by it's self including checking blind spots, changing lanes, taking exits.