Speaking on the subject Chibnall said:
"To be honest, the canon of Doctor Who is filled with amazing characters..... I’d love to see Ace back, I’d love to see Tegan back, I’d love to see Amy and Rory… the list goes on."
Chibnall also spoke about a certain fan favourite who sadly cannot reappear because of the actors passing's -
"I would really love to bring back Sarah-Jane..... People working on the show now worked with Lis Sladen and everybody still remembers her so fondly and talks about her a lot. I would love to see her with the 13th Doctor"He also spoke about the Fourth Doctor's companion Harry Sullivan -
“I would love to have brought back Harry Sullivan too, played by the wonderful Ian Marter from Tom Baker’s first season. I would have loved to see Sarah and Harry nowadays to check in with them.He added -
“It’s a credit to those actors.... They are indelible in my life and memories and those of many others. It’s so sad that they’re not with us anymore.”