Uninitialised memory in development tools can have very interesting results! There's a Game Boy Color game that contained HTML from a porn site in an uninitialised region: https://tcrf.net/DynaMike
so did that mean...the game itself could be theoretically 18+ since it contained implicit references to pornography?
While there is precedent[0] for reclassifying a game based on content included on the distribution medium but not normally accessible within the game as released, I think you would have a hard time making that case here since you're probably going to have a much harder time inducing a GBC game to render an HTML document or JPEG image.