No, I think that it is legal. And I have the following reasons to think so:
- a NoCD crack is something that helps piracy. The game is made on purpose to search for the CD, and if you try to trick that mechanism, it means you are not respecting a license, thus doing piracy. NoCD crack is used only by someone who owns a pirated game. Of course some people would use a NoCD patch even if they own the game, but this is not the case that cause NoCD cracks to be forbidden. And those are very rare.
- we are not allowed to post original Civ3PTW/Civ3Conquests files, but if we are allowed to post modified graphic files, we should allowed to post modified exe files too!
- may not be considered an appropriate reason: many other games have mods that alter the .exe file, and it is legal to post them. And if the license does not restrict us from posting modified .exe files, why would it be illegal to do so?
So I think that it is legal! Especially as long as we can prove that this changes can not be used by pirates to pirate Civ3, nor can they help them do it, we are all right.