I believe that Kaby Lake brings support for LPDDR4, whereas Skylake doesn't have it. Apple only uses LPDDR on its laptops, so you can't get 32 GB as this would mean DDR4 and higher power consumption.
KBL supports LPDDR4 and SKL doesn't. The current Macbook runs SKL.
Re:Switching from macOS: The Basics
by Anasufovic on Thursday November 03, 2016 @12:00PM
(#12865108)
Optimism
Can you comment on why you think this is true? A cursory look at Kaby Lake does not seem to indicate any sort of intrinsic change that would allow the MBP to have more memory.