Given the punishing training regimen the Williams sisters follow, it is good evidence of biological limits on the boost training can give in tennis. I doubt it has much relevance for creativity.
I think it's pretty well accepted that Men better at physical activities almost across the board. I don't think that's what the original point was about though.
The original question was asking for an example of a "genetically talented that they didn’t train" losing to someone who was a "pro" and this is clearly not an example of it.
That said, I'm not trying to make the argument that there aren't 'genetic' limits.
The original question, however, was a loaded one in the context it was asked, in that the person asking the question was using it to dispute the claim that individuals have biological limits that training cannot surmount. Even if this answer does not fully satisfy the excessively stringent terms of the question, it still works as a counterexample to the questioner's position.
For a majority of aspiring athletes, it is probably better for them to accept sooner rather than later that they cannot get to the first rank - and most of them do. Unrealistic expectations in either direction do not help (though a bias to optimism is probably a good thing.)
But, as I suggested earlier, I don't think the issue of athletic performance has much to say about creativity, which is the topic of this article. Indubitable's answer of Ramanujan is a much more relevant reply to your question, but where does that leave us? His example does not give us a reason to give up on creativity, which goes to show that the question doesn't address the issue.
I also wonder though how much of a difference it makes that the Williams sisters presumably only train with or to play against other women.
Let me say that I don't disagree in the advantages of genes and sex, but from my own experience competing at a moderately high level and knowing players who competed at the highest levels, you more or less train with an expectation of what your opponents will do in mind.
At least in badminton, the way men and women play the game is completely different, but I would be very surprised if it's merely due to physical differences. I don't think it's due to physical differences because the difference in style shows up across the skill level, and I imagine a professional female player who consistently did weight training should be able to achieve the same level of strength as a male who isn't nearly as serious.