It is not known publicly yet if the new cross-platform SDK for the D415 and D435 cameras supports Windows. But even if it does, since it should not be compatible with the previous cameras, the Windows RealSense SDK would be discontinued in the sense of the end of further software development for the SR300 beyond the '2016 R3' version.
The basic Librealsense does not have skeleton and person tracking. The RealSense SDK for Linux though, which installs Librealsense as one of its modules, has these features. It is only recommended for use with the ZR300 model of camera though.
The page linked to below lists the sample programs of the SDK for Linux under the heading 'Samples for the for Intel RealSense for Linux Person Library'.
All is not lost if you do not have a ZR300 camera. OpenCV: apparently has the ability to do a form of person tracking.
It is good to know that D415 and D435 cameras may supports Windows.
MAY support is the operative word. I can't make promises, because I don't know myself yet.