They're called "legacy strips." Comic strips that continue to run after their creator has retired or died. In some cases, the creative chores are handed down to the creator's children, or even grandchildren. In others, a new team is brought in to continue the story.
I've commented on them before. Sometimes the new team revitalizes the strip, as in the case of Dick Tracy (Mike Curtis and Joe Staton the latest of several to follow Chester Gould). Often, the team just maintains the strip without introducing any new elements. In essence, keeping it on life support, like Beetle Bailey (Sons Brian and Greg Walker taking over from father Mort Walker). And sometimes -- as in the case of Peanuts -- the old strip is just rerun.
That was the point of Mark Tatulli's recent sequence with the Rerunuts. And that's definitely the point of this Lio panel (click on image to enlarge).
The Peanuts strip is dead. Yet it keeps walking around the comics page. Which makes it, in my opinion, not a legacy strip, but a zombie strip.
I'm with Tatulli on this one. Every single Peanuts daily sequence is available in multiple book collections. Charles Schultz's creation was brilliant, and it's been preserved. Peanuts won't go away -- really. Can we not get this off the comics page and make way for something new, relevant, innovative and (dare I say it) -- alive?