Doctor Who is about to get a fresh start, not just without Peter Capaldi but also without former showrunner Stephen Moffat. According to the Mirror, BBC wants to have a "clean slate" for the sci-fi show. In 2018, Chris Chibnall will take over as showrunner, replacing Moffat. With declining ratings and merchandise sales, it makes sense why the network would choose to make this move.
A new actor will replace Capaldi, who was fantastic as the Doctor but it looks like BBC is not happy with the recent seasons, and how it failed to reach the younger audience. There will also be a new female companion, so that means Pearl Mackie's run as Bill would be short-lived. Acording to the Mirror's source, "BBC management wants a return to the format from the David Tennant era, when you had a dashing male lead and young female companion."
Doctor Who is still getting a Christmas special this year, and apparently, it will focus on superheroes. Read more about that here.