Ok, here ya go...
The problem is that the current for the 5 VDC signals is very low, in the millivolt range, and it doesn't transfer well through paint. When you inspect the grounds, you will find that the wires and ground terminals are adequate, but Ford has either failed to provide instructions to the paint-prep section of the production line, or they have hired some dipshit workers who are too lazy to tape/mask the contact points for the ground terminals to contact the metal of the chassis. In fact, they have paint all the way down into the threaded bolt holes. These errors in the paint process result in poor connections for all the electronics, especially the small signals.
And to answer the "why only 2016", it isn't only 2016. My 2014 had issues not long after purchase with dash lights and other problems similar to those posted here. After a few trips to the dealer, I decided to fix it myself and was quite successful as always. Ground circuit problems will be varied and intermittent, which is why many have similar problems that seem to go away every once in a while and some are just "hard broke". Ford (and all brand) service technicians are simply parts swappers. Most don't even understand basic electronics, so there is no way they will figure this out.
When you folks having these problems decide that you're ready to have them go away, take responsibility for it and fix it yourself. Maybe Ford will eventually get to the actual cause, but it may take a few more years. Constantly bitching about it on a forum will not speed up the fix.
All of the ground points on the car have this issue, but most are 12VDC at several amps of current and while not immune to the problem, they have an easier time passing the larger currents. Those most relevant to the HVAC issue are identified in post #72. You can purchase the car wiring diagrams manual with a simple google search. I also posted a link somewhere in this thread.