I just purchased a 2016 Canyon, i don't find an option to even check for an update, it is an SLT with Nav and the 8" screen. OnStar had an issue enabling their software, I may run by the dealer on Monday to see if my system has a problem.
I found this some very good information
https://www.corvetteforum.com/forums/c7-tech-performance/3759311-hmi-2-5-2-0-1-1-1-0-specifications-and-radio-firmware-versions.html#post1591200351