I think the logical behavior for
$C:\emacs\bin\emacs.exe --script test.el
would be the same as for
$C:\emacs\bin\emacs.exe --script test.el < NUL

Currently,
$C:\emacs\bin\emacs.exe --script test.el
is still interactive -- the process doesn't finish unless user inputs ^D
interactively.

Best wishes,
Andrey Paramonov