"The keyboard has a membrane under the keycaps to prevent debris from entering the butterfly mechanism", state the Canadian and European versions of the document.
Now, MacRumors has obtained an internal document in which Apple has confirmed that the third-generation keyboard in 2018 MacBook Pro models is indeed equipped with a membrane to "prevent debris from entering the butterfly mechanism".
The document is noted to be the Service Readiness Guide for the latest MacBook Pros, distributed to Apple Authorized Service Providers. The procedure for the space bar replacement has also changed from the previous model. Previous generations of the 13-inch MacBook Pro only featured two full-speed Thunderbolt 3 ports due to CPU and bandwidth limitations.
Dust, crumbs and lint clogging the shallow travel of the keys were found to be a culprit of the keyboard problems that plagued users of Apple's last-gen MacBooks, with reports noting that this caused keys to get stuck and fail.
I'd like to see performance tests on more Core i9 MacBook Pros before passing final judgement, but until then I'm skeptical Apple's new top of the line laptop offers true top of the line performance.
Apple publicly stated that the new 2018 keyboards were redesigned for quieter typing, but it would seem that this is probably just a side effect of the membrane and not its true objective.
Apple maintains that the sticky-key problem wasn't widespread, but the company was hit with a few class-action lawsuits because of it. Also, according to MacRumors' report, third-generation keyboards that feature this membrane will not be offered as replacements in the fix program. It resembled the silicone barriers that are beneath the new keyboard keys of the new MacBook Pro.
That's because the 15-inch MacBook Pro's built-in cooling system couldn't keep up with the intense heat that the Core i9 produces as a result of its incredible performance.