Why was the protection upgrade made in the middle of a model year ... after January 2019? Our 2019 NX was built prior to Feb/19
This whole situation and your question give me a strong sense of
déjà vu and takes me back about 6 years or so. My apologies in advance if I wander and meander in my comments and replies to your question.
The IIHS crash and safety tests since 1995 have actually been a moving target or a never-ending game of cat-and-mouse, if you will. A set of standards are set by them, carmakers hustle to meet them, and soon just about every car on the market is a Top Safety Pick. So IIHS beefs up the standards again, and the cycle begins anew.
On the sidelines of the January 2013 Detroit Auto Show debut of the 4th-gen Lexus IS, I received an invitation from Randy Stephens (chief engineer of the 4th and 5th-gen Toyota Avalon) to visit the Toyota Technical Center in nearby Ann Arbor. Their main preoccupation at that time, however, was dealing with the newly-established (on August 2012) IIHS driver-side small overlap frontal crash test. The XV50 (7th-gen) Toyota Camry was launched a year earlier (August 2011) and, thus, was not engineered for this new test. Meanwhile, the Toyota Camry-rivaling 2nd-gen Ford Fusion (unveiled on January 2012) was, nonetheless, engineered so that it passed the new small overlap test with flying colors, while the Camry received a Poor grade in this test. Keep in mind that the early XV50 Camrys met the letter of the safety laws applicable at the time. The IIHS small overlap driver's side test is something over and above the minimum legal safety standards.
Even as Toyota engineers scrambled to redesign the XV70 Camry's structure to pass the new offset driver's side crash test, the soonest they could put the revised Camrys into production was December 2013. Thus, you have 2014 model year Camrys built before December 2013 that received a Poor grade in Overall evaluation; Structure and safety cage; and Driver restraints and dummy kinematics criteria, while those built after that date (labeled as 2014.5 model year Camrys) received an Acceptable rating in those criteria. (For more on this, visit the
2014 Toyota Camry page on the IIHS website).
But IIHS, as usual, couldn't leave well enough alone. On their
About Our Tests page, they note that "Discrepancies between the left and right sides of vehicles spurred us to develop a passenger-side small overlap test and begin issuing passenger-side ratings in 2017".
My gut feeling is that we're looking at a repeat of the 2014 Camry situation with the 2019 NX, where they had to reengineer the front structure to meet the new passenger-side small overlap crash test and weren't able to put the revised structure into production until January 2019.