There has been a 'rumor' for sometime, that newest LEGO Technic sets started to ship with a new design of the '16 Teeth Gear with Clutch' (6542).
Presumably the new design won't have the small teeth, on the hole rim.
Today I saw a first image of the new part, through the BrickLink database.
You may find it here: '16 Teeth Gear with Clutch, Smooth' (6542b) , as part of the Unimog inventory.
I can't be sure about the motivation for the change, but I guess the original molds may have reached their end-of-life and it was time for a revision.
Never saw it used in a set or even a MOC (there are still many things I never saw...), but the traditional crown fits some old parts (e.g. the original Toothed Half Bushes, Type I and II - 4265a and 4265b) which had the same type of crown and have disappeared from production long time ago.
I presume the new mold with smooth finishing, has superior production yield rates, requires less maintenance and cleaning. Not to speak about production costs...
Which other aspects, may have motivated the change?
Always wanted to know more, about the parts design decision process.