No, in Classic Who many of the writers retained at least some rights to the creatures they created. Terry Nation held the rights to the Dalek character, while the BBC holds the rights to the Dalek design.

So if the BBC wants to make a Dalek episode, they need to get permission for the character from the Nation family (Terry himself has passed away.) If the Nation family wanted to do a spinoff with the Daleks (as Terry himself tried to do in the late 60s,) they would need the BBC’s permission to use the same design.