It's not irrelevant, they're pretending it's irrelevant. All the trans athlete research in the world doesn't count in this case because the subjects weren't "elite" enough, seems to be the claim here. And even under the protection of that particular claim, they couldn't bring themselves to write the words "trans athletes have a physical advantage in many situations," if that is their claim. Instead we get a clinical and blatantly obvious sentence with all aspects of association with trans people removed from it. "Existing research shows that higher levels of testosterone do impact athletic performance."
But either way, the timeline remains the same. NPR tweets something that is clearly untrue, the tweet remained up for at least 24 hours, about three to four days later a correction tweet was issued, and this happened only after a community note was written pointing out the incorrect information. At the most charitable interpretation, NPR made a mistake and community notes helped them correct it. That's a good thing. Here's another example of a good correction people should know about, considering I've seen the same picture posted on GAF:
THIS IS NOT A REAL SCREEN SHOT. As the community note explains:
I will say that the community notes feature should be made a part of the embedded tweet. That's an oversight that I hope gets corrected