A license can't affect the copyright of any other code. So Hancom is just in violation of the GPL and has lost its right to use Ghostscript; it's not automatically GPL'd.
This is correct. Without a license, Hancom is liable for copyright infringement of the Artifex code if it continues distributing its product. It will be forced to either buy a license or reform its product to use an alternative, but it won't be forced to release its source code.
