I saw posted on a Facebook group that they are practice leotards, and there was a photo of their competition leotards they are waiting for- even less gymnastics like imo- they are laced in the back with dangling strings and a weird fabric twist. Super pretty for a leo, nice for a dance leo, but odd, odd choice for a gymnastics leotard. I cannot see how anyone could wear a bra with them.
I have noted that gym seems to have only one type of body on their team. Possibly they don't worry about lack of coverage/ undergarments due to the body type they recruit/ choose for their team?