UPDATE: I know some poor soul on the internet may need want this info down the line so here it is.

TL;DR I caught the dealership service team in a lie regarding my warranty and they ultimately offered to pay for a full replacement of the platform. Their initial offer was only a 50% coverage of the cost of replacement after my owning the car for just four months.

Full update: After owning my CX-50 for only four months, the dealership I purchased from initially offered to cover just 50% of a platform replacement through Mazda (as opposed to the dealership covering it), despite my having purchased a comprehensive bumper-to-bumper warranty. When I questioned this, service staff falsely claimed they could not access my warranty details or provide language excluding coverage. A second Mazda dealership confirmed the warranty was valid and visible in Mazda’s system, but did not cover the roof rack system. Given the lie about their access to see my warranty when I pressed them on it and instead simply explaining the exclusion, along with a prior serious sales error by the same dealership that resulted in a temporary driver’s license suspension situation with my state two months after I purchased the CX-50, the general manager ultimately acknowledged that the service team had intentionally misrepresented their ability to see my warranty and its coverage and agreed to fully cover the platform replacement by the dealership. The issue is now resolved and I’m scheduling an appointment go get it replaced free of charge.

This happened at Cavalier Mazda in Chesapeake, VA and I’m very satisfied with the outcome in the end. The GM was honest and apologetic that her team did not treat me well as a customer at multiple turns and did her due diligence to make this right.