It’s just a technicality. The gendered leagues don’t need to exist in the first place. But since they do, cleaving to the rules helps maintain the sense of fairness for all the cis folks. Say, if someone was a teen champion, they would no longer be the teen champion once they aged past their teen years. They become a former teen champion.
I agree it’s fundamentally rooted in transphobia, it’s literally a compromise with it. But I find that preferable to an outright ban of even acknowledging transition in the first place.
And yea, we’ll have to see how they handle it. I definitely noticed them opening the door for foot dragging. It’ll ultimately be up to whoever is actually in charge of their investigative wing though. If they actually are fair about it, this could be a step forward.