Speaking of the new butterfly keyboard, iFixit has put it through some testing:
We pumped this keyboard full of particulates to test our ingress-proofing theory. We started with a fine, powdered paint additive to add a bit of color and enable finer tracking. Lo and behold, the dust is safely sequestered at the edges of the membrane, leaving the mechanism fairly sheltered. The holes in the membrane allow the keycap clips to pass through, but are covered by the cap itself, blocking dust ingress. The previous-gen butterfly keys are far less protected, and are almost immediately flooded with our glowing granules. On the 2018 keyboard, with the addition of more particulate and some aggressive typing, the dust eventually penetrates under the sheltered clips, and gets on top of the switch—so the ingress-proofing isn’t foolproof just yet. Time will tell how long the barrier will hold up. Following the Mythbusters method of testing, we pushed the keyboard to failure with the higher-grit particulate we used last time: sand. And just like last time, a few poorly placed particles bring the mighty butterfly down to earth, never to click again.
I’m hopeful that this means in everyday life, these things will be as robust as the 2015 and earlier keyboards.