Sounds like the diagram told you what you needed to know, now you just need to find its mate.
I wasn't implying you had a UK bike, just "thinking out loud" about what the connector might have been for. Like the TPS connector, all (or most) of the bikes built, regardless of market, got the wire harness provisions for carb heat. Only certain markets, like UK, got carbs with carb heat, so if you didn't have the heated carbs, you'd have a connector with nothing to mate to..