I think the athlete wins even more. He wins the low hurdles - just like TJ not one of his normal events but he's still better than a rando. He also wins the 200. Hammer? Quite probably. If so, he sweeps sprints, throws, and jumps.
I used to think about Eaton in his prime when males competing in women's sports was either just beginning or just being noticed, or just becoming controversial. So, you could say Mayer or Jenner, or whoever is the current king of the deca. This was not my idea, I read it somewhere, but the gist was: how many events could Ashton (a few years ago or whoever is great when the experiment takes place) win in the women's division of the next WC or Oly.
I always thought he'd pretty easily win every sprint with one exception: the High hurdles, since the on the 100 they're closer together than the 110 and he was pretty tall compared to Sally Pearson et al. Still, he wins it. So that's 100, 200, 400, and both hurdles. All jumps including triple. That's 9 Golds. 3 throws he does all the time and maybe hammer. So 12 for sure. Some have thrown the 800 out there, but I'm don't buy it. So let's say no hammer, no mid-D. And that's against the best of the best women's athletes. Just 12 Gold. It's hard to argue against this. I don't think it would be much of a contest.
So the real question is: are random dudes better than the absolute best women? Not even close. You don't know a 20 year old non-runner who could beat Genzebe Dibaba or Sydney McLaughlin. So our hero in this hypo loses the 4x400, maybe the steeple and 5k. That's a maybe, since they can certainly break a 5-minute mile, a benchmark I'm betting anyone who hasn't ever run a continuous mile can get. So all sprints, throws, and jumps. This would be easy. 800, 1500. Deca 1500 times are faster than gun-to-your head forced gym class times by a lot. So mid-D no problem. The only X-factor would be relays and distance. Overall meet score would be a blowout.