For me, there were three key parts to this video:
At about 1:32, you’ll see a walkthrough of the stack that makes up an individual butterfly key. Here’s a tweet with all the piece in one place. Makes it a bit easier to see.
At about 2:38, there’s a closeup look at the dome switch cover, where the change in materials seems to have been made. The new dome switch cover is nylon, a more “robust” material than what was used before.
At about 3:58, you get a closeup of the old and new dome switches.
Not sure you can really draw any conclusions from the video, but I did find the closeup look at the mechanism interesting.