Gender stereotypes have nothing to do with this. It is entirely a red herring being used to dismiss the term "cis" which was and is a term used by scientists to distinguish between people who are born women and people who choose to become women. who are known as "trans" women. Suppose for example there was medical research into osteoporosis and some anomalies were found, if this could be related to the involvement of 'trans' women and was not evidenced in the 'cis' women involved, it might be very valuable information.
The only gender stereotypes around are the ones you choose to accept and most young people know this.