Past games gave players a huge amount of customization options when creating The Boss in Saints Row, which covered everything from voice to size of genitalia.
The player will no longer play as the Boss of the Saints, but as a new up-and-comer trying to take them down. In order to accommodate this, the events of Saints Row 4 and Gat Out of Hell will supposedly be retconned as events which took place in a Saints Row TV show developed by this new corporate iteration of the gang. First, the game is said to take place after the events of Saints Row: The Third, with the Saints having become a soulless megacorporation after the death of Johnny Gat with the former player character – the Boss – at its helm.
One major rumor is that Saints Row 5 will be something of a soft reboot for the series, with some big implications.