Has not happened on my MacBook Pro 16 inch after 2 months. Will check in one more month. I know this is a very common issue. However, the coating on this Mac is particularly more resistant to wearing compared to the MacBook Pro 2016-2019 as far as I have seen (with Butterfly mechanism) . Usually the older models become shiny after just a few weeks. I guess we got luck that it takes a few months rather than weeks.
That's not my experience, I've 2008, 2011, 2012, 2014, 2015 MBP's still in the house and the newer models the keyboard's polish up far faster. The new 16" I can't speak of, equally anything past 2015 the keycaps have polished in a matter of months in my own use.
Worst being the 12" Retina, within days the keycaps were obviously polishing up, very far from what I expect from a premium notebook. This baseline Asus the keycaps are still matte after close to two years of professional use, just what exactly is wrong with Apple today...?
My well beaten 2011 15" MBP still has matte keys after numerous years of abuse across multiple users. Over 102 months of use. Just maybe "someone" once had higher expectations of the Mac & Apple. Not to cheap out and save a few cents on the build quality, as seems to be the case today...
Q-6