Something to consider is that many of the advantages that the article says women have might not be as relevant in the context of "one-off" events (even something smeared over a few days).
One advantage listed pointed was the higher fat stores, and a higher preference to burn fat rather than burn muscle. But modern food and fueling strategies (and this is of course race/event dependent) can also erode that advantage. If you can continuously dump glucose into your system at the right rate, you'll limit your body's need to tap into muscle or fat stores at all. In this race, you can carry whatever you want in your pack during a lap, and every lap you have the opportunity to refuel and pick up more food.
The timescale that this race occurs over probably isn't enough for the recovery advantage to really show, but uh... I've never run an ultra (or a normal marathon...), so I really can't judge.
Finally, the very nature of races (and having a time cut-off) is just soooo different from if endurance hunting for your life style. In a race, burning up all your matches to just barely cross the finish line in time (or at all) is a winning strategy. In real life, burning all your matches to catch an animal on a hunt is -generally- not a winning strategy (if it means that you'll be in recovery and shit at hunting for the next 2 days). If hunting-gathering is your life, your strategies should be built around consistency and risk management. Many of the advantages listed in the article seem like powerful tools for risk management. As your sport (or your metric) better approximates the risk management scenario of "life as a hunter-gatherer" I think you'd expect the female advantage to show more prominently, and maybe eventually dominate.