Based on the documentation from Microsoft, modern versions of Windows use Windows Socket version 2.2.
This particular parameter which sets the value of iMaxSockets is only used in the Windows Socket 1.0/1.1 implementations and is/should be ignored in all 2.x implementations, which may explain why you’re not seeing this in modern Windows versions.
I’ve resubmitted a patch to remove the define and replace the variable used for iMaxSockets.