Rugby, NFL football, hockey, boxing, and even WWE professional wrestling all have histories of multiple athletes suffering from CTE. Women’s hockey I think will have fewer incidences of CTE due to rule and equipment differences but it’s still early to say. We often didn’t find out about CTE in men’s hockey players until after they died young in retirement.
I have no idea what the rules for women’s rugby are like, if there are any differences. The real issue is a swinging motion of the head (caused by falls or sudden stops), not unlike the way a hammer swings. The movement of the brain inside the skull with sudden stops or changes of direction causes tearing like you’d expect if you swung around a bucket of jello and then slammed it against something.
I try to be cognizant of these things and not support these sports so much, yet they’re in my social circles and I do enjoy them. Every athlete makes their own choice to participate in these sports at the end of the day, though I wonder how informed they are about the risks.