My MacBook Pro (2016) just needed another top case replacement, as keys did not work as expected. Since the last replacement, Apple has established a Keyboard Service Program for MacBook and MacBook Pro and introduced a (more or less) protective membrane in recent MBP keyboards.
When I picked up my repaired notebook (not from Apple directly, but an Apple Premium Service Provider) I asked if the replaced keyboard has this membrane. The staffer couldn't tell, but said that this has recently been the case for “some replacements”.
Can I somehow identify which keyboard/top case generation is installed? Is the membrane visible?