Since it is not quite officially announced that Gold Edition is being released, I plan to update this with info on it as soon as it is available. If I'm not able to, this is what I have in mind, adding this under the Game of The Year entry:
=== Gold Edition ===
{{++}} Contains all Game of The Year content, Gods and Kings, Wonders of The Ancient World, and Korea.
{{++}} Most complete version.
So if someone gets here first (only once it is released), that's ready to go in the article.