Exchange old MacBook keyboard with newer I have a MacBook Pro from Late 2014 (I think). As you know, Apple introduced a new keyboard-mechanism (called Butterfly). Some of newer MacBooks have these technology already built-in.

It is possible (based on hardware and compatibility) to upgrade the internal keyboard, means remove the old keyboard, get a newer keyboard with butterfly-mechanism and insert it to my MacBook?
No, it is not possible. The keyboards are not compatible.