One case centers on a trans girl who, because of puberty blockers, never went through male puberty. Can she be prohibited from joining a girl's team? Relevant to her case, after the Skrmetti decision, she can be barred from accessing these puberty blockers altogether. Right now it depends on state law, but it's clear that RFKJr's FDA will be taking a look at national restrictions.
The other case (as far as I can tell from a first read) centers on a young trans woman who did go through male puberty, but then was on hormones long enough -- under some sports-specific standards -- to try out for the women's team. Another plaintiff in that case is a non trans woman who highlights the invasive nature of the Idaho law: in order keep out trans women, any woman or girl's sex can be challenged, followed by a process to determine whether that athlete is trans.
Let me say that again: the Idaho law means any woman or girl can be subject to a determination of their sex, with the goal of keeping the very rare trans girl out of girls' sports. And indeed, there have been far too many instances of this, where the vast majority of the challenges turn out to be targeting non trans girls.
As a side issue, the Idaho case includes the misuse of scientific research on testosterone, according to the author of the misused research study. While not the focus of the case, the misuse or "cherry picking" of research has played a prominent role in the right-wing attacks on medical care and bodily autonomy. So far, it has been nearly impossible to effectively counter this tactic. Lies get inscribed into law as if they are truth.