I’ve read the HG publishing information, but it didn’t list specific information about market projections, so feel free to ignore this if I’m wrong, but it seems to me that it COG reviews a submitted HG game and determine that controversial themes (which do not violate the guidelines) negatively affect market projections to such an extent that releasing the game would be a monetary drain, then it would make sense to reject the game without updating guidelines.
I also think it’s worth pointing out that we’ve already been having a discussion on what exactly the guidelines means (what is glorification?), and COG’s interpretation of their own guidelines might differ from mine or yours, and ultimately we have to accept their interpretation since they are the ones publishing the game.