Why don't the US Navy Blue Angels fly Super Hornets?
The USN Blue Angel demonstration team is transitioning to Super Hornets. According to this press report:


  “We are supporting the Navy’s plans to transition the Blue Angels to Super Hornet aircraft from classic Hornets by providing engineering for the necessary conversion modifications. ...,” Paul Guse, a spokesman for Boeing, said Thursday in an emailed statement.


The transition will take some time for carrying out the necessary modifications including...


  ..., installing flight auxiliary fuel pumps that can operate in sustained inverted manoeuvres and inserting an oil pump in the tail to emit blue smoke. 


...among others. Also, as the aircraft performance is different (the Super Hornet is larger and heavier, for one thing), the aircrew will have to train on the new aircraft before participating in any airshows.

A lot of the weight difference may be handled by removing the combat hardware but the size and handling characteristics will require a lot of training and practice time before the super hornet can be used in the precision flying exercises used in air shows.