It's not undiscovered. It's known. But it's not a difference in average intelligence (there is one but it's miniscule), it's a difference in distribution. Women tend to cluster more towards the average, man are spread out more in both directions. Or to put it another way, in any given population large enough for the trend to show, there will be more very smart boys than very smart girls, but also more very stupid boys than very stupid girls. The mean of both groups will be almost the same however.
Unless you are debating the reasons for the pattern rather than that it exists, in which case yes - that's an ongoing topic. But I don't think housework can account for a smaller distribution of IQ, (Nor do full time jobs, of which men are more likely to be doing, allow for a lot of free time for chess, fwiw).
In any case, I think Nellodee had the right of it, already. And toomanycoats gives a good example of its outcome. Chess is a niche hobby that takes a lot of time to get really good at. So in so far as it requires natural talent as well - which it does - the overlap of boys who have talent and the interest and girls how have the talent and the interest, is going to be significantly smaller in the latter case. But this is still different to athletics. No woman is as strong as a competitively strong man. At least, not that I know of. It's a question of actual limits. There isn't equality of ability. But in highly intellectual pursuits, there's equality of ability, just not equality of numbers. I personally am not a fan of sexual separation in hobbies that don't require it. Like chess. It doesn't matter to me if there are fewer women in the hobby so long as it's not a result of women being prevented from pursuing it.
Ultimately though, it should really be the choice of the people who play it. If there are enough women to do so and they want to create a women's league, they have the right to do so and there's nothing wrong with that. I think there would be something wrong with it if that meant that other tournaments were only for men but that's not the case. You have women's leagues and mixed leagues. Gary Kasparov may not have believed that women could be chess champions but he never tried to stop them from competing. So I think it's fine. Women have both a women's league which can encourage women in the hobby and full access to the mixed league to compete against other humans in general. Best of both worlds.
Barring the odd big-footed kenyan. ;)