The only changes I can recall for the decals was an update to the foglights and rear exhaust decals in 2016, the same year that Ford rolled out the updated Fusion. The headlights, grills, and taillights all effectively remained the exact same all 5 years Chevy used the SS. Of the 9 years that the Gen6 car has been used, only 2 of those years have there not been some sort of change in manufacturer branding that I have noticed:
2013: Original decals and body shapes.
2014: No changes from 2013 visuals
2015: New Camry
2016: SS Decal update, Revamped Fusion nose and general decal update
2017: New New Camry
2018: Camaro replaces SS
2019: Mustang replaces Fusion; Camaro taillights changed early into season; Toyota does slight branding update (no vehicle decal change) late into the season
2020: No changes (somehow)
2021: Revamped Camaro nose and general decal update