The gang at iFixIt, which tears apart electronic gadgets and looks at their innards so you don’t have to, is in the middle of tearing down the new MacBook Pros and have found that Apple has cocooned their butterfly switches in a thin, silicone barrier.
Here’s their initial take: “the advertised boost in quietude is a side-effect of this new rubbery membrane. The flexible enclosure is quite obviously an ingress-proofing measure to prevent the mechanism from seizing up under the brutal onslaught of microscopic dust. In fact, Apple has a patent for this exact tech to ‘prevent and/or alleviate contaminant ingress’.”
Apple says the new MacBooks sport an updated, "quieter" keyboard, but haven’t mentioned a fix for the problem of butterfly key failures. Apple downplays the number, but some MacBook and MacBook Pro owners have experienced some type of failure with Apple's butterfly keyboard, thus rendering the machine useless. Specifically, small amounts of dust or debris impede normal switch behavior, causing keystrokes to go unregistered.