No, they didn't. First, they pretended the issue didn't exist, while charging people hundreds of dollars for new keyboards. Then, they announced a "quality program", where they'll replace your broken keyboard with another, equally defective one for 4 years. So after the 4 years is up, your keyboard is going to break again, and you'll have to pay again or get a new laptop.
"improved" was a non-sealing dust jacket and even then apple was too chicken-shit coward to say it was an attempt to keep foreign particles entering the hinge. Apple called the addition a noise masking element, in my opinion an attempt to avoid giving evidence for any litigation against them that may come up.
Maybe this is all great business sense, but it really makes me consider if buying another apple laptop is a good idea.
While they did change the keyboard design in 2018, there are still reports that the "improved" keyboard is failing as well: https://www.reddit.com/r/applehelp/comments/9w6vk3/macbook_p... https://www.reddit.com/r/applehelp/comments/9w6vk3/macbook_p... https://twitter.com/kapeli/status/1090640259921166336