There's something wrong with your laptop, the new MBPs shouldn't do that in my experience. I'd recommend visiting a Genius Bar near you!
All of the laptops do that when they reach thermal limit. You can see that behaviour with Intel's power gadget.
(And yes, pattern appears on all MacBooks we have in the company, just at different points. The 2016 locks down the CPU when it reaches about 85 degress C. Even some new iMacs do the same due to inadequate cooling.)
My top spec 15" touchbar MacBook Pro happily locks it's 2.9GHZ CPU to just 1.2GHz after less than two minutes of running anything intensive (including games) and gets too hot to hold in the lap.