The joke, for anyone else here who isn't a book nerd (my wife is), is that now whenever an old author dies with unfinished work, or hasn't finished their work (that's you, George!) people make a joke "Just let Brandon Sanderson finish it!" because Mr. Sanderson is an absolute writing beast, he's a "100x writer" if there ever was one and he is working on (or finished?) a book series[0] by a now-dead author and most people think he made it
better.
[0]: https://en.wikipedia.org/wiki/The_Wheel_of_Time