pipAT
I guess the old Vienna Imperial is also delievered in 16bit 44.1khz audios. But Truekeys used to show on Machfive player, and it was much larger in size than its UVI version. Of course, there are developers who are willing to offer diffferent bit depth versions like Impact Soundworks Pearl Grand, Production Voices Grand 2, Premier Sound Factory Kawai Legend etc. Also there are wars between 16bit vs 24bit, and 44.1 vs higher frequencies. Discussions about these have been going on for years in Gearslutz or now Gearspace.
Acousticsamples released a Kontakt version Kawai EX in 2010 or so, later the developer did a UVI version which is only 1/10 the size of Kontakt one. I tried both versions. The difference I could sense was quite subtle. I kind of felt the Kontakt was warm and thick. The UVI was bland like boiled water. I wish had nulltested both versions to make sure there was difference.
For me, there is difference, but at a cost. I am totally fine with 16bit 44.1khz products.