https://www.thewrap.com/doctor-who-stars-bradley-walsh-tosin-cole-to-exit-after-holiday-special/

“Well as the Doctor I will say that the fam as a four is no more,” Jodie Whittaker said of Walsh and Cole's appearances in the Revolution of the Daleks New Year's Day special. Doctor Who boss Chris Chibnall says the storyline in which Graham and Ryan leave the series in the holiday special is “very emotional” and the team has “been in tears watching it."

Why is Bradley Walsh leaving Doctor Who? He was the one that made Doctor Who a ratings winner and BBC got huge ratings for Doctor Who because of him. My guess is that BBC is not giving the Doctor Who costars a bigger salary because of the short seasons. As for Tosin Cole leaving as well I think they should've let her leave instead of Bradley Walsh but now that Bradley and Tosin are out I can predict that Jodie Whittaker will be the next of the Doctor Who cast to go and Doctor Who will be cancelled. Something fishy is going on with Doctor Who but at least Bradley Walsh will still have his game show career and singing career too
Bestie