Incorrect. The ability to be creative can be improved by increasing your skills and intelligence. I'd argue that creativity and intelligence go hand in hand. Any person who becomes better at something will also become better at being creative with it, particularly when they practice the creative aspects.

The key question is, which of the following is true:

Creativity is a subset of intelligence
Intelligence is a subset of creativity
Creativity and intelligence are overlapping constructs
Creativity and intelligence are part of the same construct
Creativity and intelligence are distinct constructs

I doubt you will find any credible sources that state that every individual is born with x amount of creativity that cannot possibly be changed through learning processes.

As others have pointed out in this thread before: Comparing fighting and dancing is not a very smart thing to do. To become better at making replays than NutHug you are gonna have to spend significant amounts of time practising. To become better than idk Logic at wushu you are gonna have to spend significant amounts of time practising as well.
I'd argue that both abilities overlap greatly in some aspects and differ a lot in others. The difference between the two is too small to make accurate assumptions without proper data.

But the success of the end result is more likely to be determined by skill for MP. In single-player nobody sees how many times you make mistakes and the end result appears faultless regardless of how long it took you to think it up. Sure you could be incredibly skilful and create a replay in one go in SP, but you can also just trail and error your way to the same result. In MP you usually need to be genuinely skilled (rather than just dedicated) to prosper (in terms of people actually respecting you).

I do not think specialists of either fields are inherently superior or inferior because of this. Being dedicated enough to the game to create a replay of a high standard despite not being able to get it right first time is a value just as respectable as being about to beat most people in a range of mods on MP.