I think he was actually trying to shy away from emphasizing on that since even Pearl was like " yeah she's gay. People are gay. People are black. And?"
So I think Moffat was trying to keep it more downlow and editors talked to the papes => papes ran with what they thought might be the most salacious part that wouldn't get anyone really in the know in trouble
also I hate when things rely on surprise stuff needs to be rewatchable, replayable, or it is not timeless fuck