The command line of an application built with cx_Freeze can be hidden with Win32GUI.
Why does cx_Freeze choose to reference Win32GUI rather than Win64GUI?
This suggests that cx_Freeze has either not been updated to include this feature, or is calling a 32 bit command and yet almost all Windows computers are now 64 bit.  
Is there a reason why the inplamenters chose to call it this?
I have researched for a long time but have not found any answer, any thoughts would be appreciated.  Thank you.
It is simply because that is how it started. Even now it is called the "Win32" subsystem, even though it is 64-bit!
Why does cx_Freeze use Win32GUI rather than Win64GUI?