Anytime there's a new chassis launched you have to expect greater failure rates on the early parts, and the 2016 model was the first one with a new chassis, so I'm not sure the data they have tells the entire story.
It's likely there were manufacturing issues that were still being worked out throughout the 2016 cycle and that there were very minor tweaks made during that year's run to improve reliability. If that were the case, the issues would be weighted toward 2016 models manufactured early in the year, and we'd only be able to know if we compared return data to build date.
In my personal experience with a 2016 MBP, one of the issues with the keyboard was that when the system was under load for a significant amount of time, the resulting increase in temperature around the left side of the keyboard would cause keys to stick. The keys would unstick after temps decreased. This was an issue discussed by several people in forums. A manufacturing change to something like the application of thermal paste on the CPU/GPU might change that, without any change to the keyboard design itself.
