It isnt about sexism considering the PF is currently being shopped around to other females. Jean doesnt have the PF right now bc the X-Office doesnt currently have access to it. PERIOD. Its been off limits for years bc Aaron has been using it and building a long tale narrative with it. The current Entre the Phoenix storyline would not be possible if Jean was Phoenix in the X-line. The X-office was lucky enough to even be able to use it as a plot device to bring Jean back but thats the extent to which they were able to