I work part-time at an Apple Authorized Service Provider and I am the person who handles the checkin process where I interact with the customer, verify the problem, provide the software support (if applicable), and/or check the system in with documentation to get it to the Apple Certified technicians (if applicable.)
Whatever Apple did with the keyboard, I agree it was not significant. But they presumably did something, because the number of 2017s at this point in time coming back with keyboard issues is a small fraction of 2016s. That's my personal observation. But I do not want to speculate to the long-term implications given how the 2017 is still a relatively new lineup and how Apple has not published sales numbers regarding 2016 vs. 2017 sales quantities.