So do producer and creator mean the same thing in terms of TV shows and movies?
...but that doesn't mean that the creator cannot be also a producer.
Simply, the "creator" is the person who came up with or developed the idea for the show...nothing else.
They may take no further part other than coming up with the original concept.
IMHO in television, creator is often used to mean someone who works on a television show, particularly someone whose input creates noticeable effects on the show as seen.
But in my opinion when someone is described as a creator of the show, using "creator" as an unofficial title, that should mean that person came up with the idea for the show and ...
I think what you're looking for is the Character Aged with the Actor trope.
An old franchise comes back after many years, but, of course, now the actors are all old. Instead of recasting or making the actors up to look younger (or using Digital Deaging), it's decided to acknowledge how much time has passed and just have the characters be that much older.