If you were hoping that Apple would replace the second-generation butterfly keyboard on your 2017 MacBook Pro with the third-generation one under its free service repair program, you are out of luck. The company has confirmed to MacRumors that its third-generation butterfly keyboard is exclusive to the 2018 MacBook Pro.
This means that even when you take the faulty keyboard of your 2017 (or 2016) MacBook Pro to Apple, it will end up being replaced with the same generation. While a replacement is going to work for most users, it will not solve the reliability issues that have plagued both generations of the keyboard.
For the third-generation butterfly keyboard, Apple has used a silicone barrier to prevent dust ingress which should help improve the reliability of the keyboard. Apple, on its part, does not mention any reliability improvements with its third-generation butterfly keyboard and instead claims that it is only quieter than before. Apple may have made some other changes internally to its third-generation butterfly keyboard which does not make it backward compatible with the previous two generations of the keyboard.
As iFixit points out in its teardown, the quieter typing experience on the new keyboard is a side effect of Apple installing the silicone protection.
When asked if Apple Stores and Apple Authorized Service Providers will be permitted to replace second-generation keyboards on 2016 and 2017 MacBook Pro models with the new third-generation keyboards, if necessary, Apple said, no, the third-generation keyboards are exclusive to the 2018 MacBook Pro.
There’s still hope that Apple might just have silently tweaked the design of its second-generation butterfly keyboard to make them more reliable. The company has received a lot of backlash over the poor reliability and performance of the keyboard due to an oversight in its design. So, despite the free service program, if Apple is only replacing the faulty keyboards with keyboards that are bound to develop the same issue again, it is not putting an end to this issue.