Parker and Stone will respond who they consistently have done if criticised.
Their argument is anyone is fair game. If you object to the trans stuff, where were you when they made jokes about Jews, black people, disabled people, etc.
I love South Park and they were way ahead of the curve on this- but often it makes uncomfortable viewing (the episode where Timmy has a cab company and another child is raped by a transwoman is pretty uncalled for but I don’t know if it was slated as heavily as women saying women don’t have penises). But yeah overall they can clearly see the issues with what is happening.