If I understand correctly how it works in the UK, then everything Moffat created (Characters, etc.) can only be used with his permission after he left, right? So what exactly does that include? And what will we actually miss?
As
Mr. Awe said, I think that anything created by a member of the show's staff belongs to the show, as distinct from something created by a freelancer. That's why, for instance, the credits of "Hell Bent" include "Daleks created by Terry Nation" and "Cybermen created by Kit Pedler and Gerry Davis," but don't include "Time Lords created by Terrance Dicks and Derrick Sherwin," because Dicks and Sherwin were on the show's staff when they created the Time Lords. This is also why Robert Holmes gets a creator credit for the Sontarans but not for Rassilon -- because he was a freelancer when he wrote "The Time Warrior" but had become script editor when he wrote "The Deadly Assassin."
And even for things Moffat created as a freelancer, like the Weeping Angels, why assume they couldn't be used again? Sure, his permission would be needed, but why wouldn't he grant that permission? There have only been a few times in the past when such permission has been denied, like the couple of times when Terry Nation or his estate withdrew permission to use the Daleks. The new series has used lots of monsters and characters created by earlier writers or producers -- Daleks, Cybermen, Sontarans, Ice Warriors, Silurians, etc. -- and Moffat was able to use RTD characters like the Tenth Doctor and Rose.
Now, whether a new showrunner
wants to keep using the previous showrunner's characters and ideas is another matter. Moffat generally avoided reusing RTD characters and focused on his own, and Chris Chibnall might want to do the same. But that doesn't mean he
couldn't use Moffat-era characters if he wanted to.
