I bought a 2016 13-MBP for my daughter in college. Within a few weeks she complained that nearly every time she closed it, it restarted on reopening. I received all manner of BS responses at the Apple Store, such as: "It's supposed to do this to make sure the latest updates are installed." and "It's a software problem." After a few months when she was home for break we took it in, also because of a stuck key. Since that can no longer be fixed without going to the repair center, off it went. It came back with a new top case (required for the keyboard) and a new logic board, as "some pins were bent." Both problems solved.
The real annoyance here is their Genius Bar diagnostics. Because hers passed with flying colors they were interested in pursuing the reboot issue. My 2013 15-MBP started going flakey in April, with crashes and screen blank outs increasing in frequency. Finally in August, I did the diagnostics. Passed with "no problems." It all-but died a week later (POST gong, and keys light up - no internal or external display). At the Apple Store it passed diagnostics again, even as it was sitting, darkly, there in front of the Genius. They replaced the display, logic board, top case and SSD.