I remember reading discussions about the topic you brought up. After doing research, I came to the conclusion, that having a keyboard cover wouldn't be a problem on my late 2011 and it hasn't been.I'm intrigued by the Moshi keyboard cover. I wonder if it would make the new 2016 MBP keyboard a bit less noisy? On the flipside, I wonder if covering the keyboard affects how the MBP releases heat? I've heard that Apple counts on all air holes/spaces in how it manages removing heat from inside. A relevant concern or overanalyzing things?
I ordered the Radtech screen saver/keyboard cover as well.
I have been using my new MBP for just under 2 hours now and while the keyboard is noticeable, I don't find it any louder than my late 2011. I do think that the new cover will soften the sound a little more.
I am really liking the late 2016 13" base MBP. The keyboard feel and response is so much better than the 2011. The sound on this Mac is amazing. It is like night and day from what I had been using.