The report claims that new showrunner Chris Chipnall will move towards what is almost a complete reboot, with a new actor replacing Peter Capaldi, the current doctor. Current female companion Pearl Mackie is also rumored to be leaving after a single season on the show. Steven Moffat, the current (and soon-to-be former) showrunner, has also announced he is leaving at the end of 2017.
The Mirror says that the network will replace Capaldi with a younger actor, in an effort to appeal to younger audiences (and boost sales of DVDs and other merchandise). They cite a network source as saying that they want to attempt to recreate the David Tennant era, which featured a handsome young Doctor.
Capaldi, now 58-years-old, has been the Doctor since 2014 and is recognized as the twelfth version of the Time Lord.