I thought I would share my problem as well, as I'm either very unlucky or there is a serious engineering issue on the MacBook Pro 2016 keyboard.
So here it is.
I ordered mine back in late November, and received it in time for the Christmas holidays.
I live in the UK, but ordered a French (AZERTY) keyboard.
After a few days (weeks?), the left-hand side Command key stopped working.
To be exact, it worked but only if you pressed it VERY hard. So almost unusable.
Thankfully, I still had the right-hand side Command key to work with.
Also, a few days before swapping it for a working one, the Tab key started double typing.
I then went to the Apple Store, and asked for a repair, back in early January 2017.
They offered a replacement, and even offered that I keep the current one until the replacement arrive in store for a simple swap. Nice !
I waited about one month (!!) because it took ages on their side to get the replacement approved.
Then, after a few calls to the Apple Store, one week ago, I got confirmation that my new machine arrived.
Went to pick it up, went back home, only to realise they gave me a machine with the wrong keyboard (UK keyboard this time).
I called them, and (after some discussion) agreed to do another swap for the model I actually bought in the first place (at first they wanted to keep the UK one and give me my broken FR one until they get the new FR one... I was pretty tired of reformatting and reinstalling and going to the Apple Store by that point so I persuaded them to order the new one and make a swap as we did the first time around).
So, as of today, I'm now working with the UK replacement, and... the "C" key is starting to fail.
It's not as bad as the Cmd key on the original one, but you still need to press it more otherwise you mistype. I'm a software developer, and frankly I don't want to spend my day correcting my sentences/code because the Cs are missing half the time. On a £ 3000 machine.
They called me back yesterday to discuss options again, and I have now asked for a refund. They are discussing it and they were supposed to call me back today to confirm. Still waiting.
I've also ordered a Dell XPS 15, as I have a feeling I'm not going to be able to be productive on this wonderfully expensive piece of crap that is the MacBook Pro 2016.
(Disclaimer; I'm a long time fan of Apple, I own pretty much their entire family of product, and I'm very, very, very disappointed).
TL; DR: On two MBP 2016 15", 3 keys were not functioning correctly. That's a lot.
So I'm either unlucky, or Apple's got a problem.