Which Mazda dealer do you usually go? I didn't bother to replace those during my last warranty service, and I just ignore the reflection of chrome AC vents on rearview mirrors.
My Mazda dealer, Town North Mazda in DFW area is very reasonable although the tech screwed me up several items whe I took my 2016 CX-5 in for last-chance warranty service. The tech originally thought my rear brakes are fine. I had to talk to a master tech and he felt my rear brakes did meet the criteria of the TSB and replaced everything for me.