i think it's still called win32 today because win32 was a massive overhaul. 16 bit windows was loaded with that far and near pointer gunk to stretch those 16 bit pointers which win32 was able to do away with thanks to larger pointer widths.

regarding win32 vs. the nt api. i'm not super familiar with the pedantic distinctions there, but i do know, much to the programmer's chagrin, the thousands of windows api functions have varying levels of kernel entry, where i always have appreciated the (relatively) small number of unix style syscalls and the clear delineation between kernel and userspace api. (although i suppose futexes blur that, in name at least!)

Well, since introduction of vsyscall and vDSO, the Linux syscalls too have varying levels of kernel entry.