Narnia is a world ripe to be filled with stories. The conquest of the islands, the ancient battles of Arkenland, the court politics of Calormen, the mines in the depths of the earth, the intrigues of the giants, the conquest of Narnia by the White Witch, the conquest of the upper layers by the entirely unrelated other Witch (where’d she come from), the neighborhood politics of the squirrels, the love story of the trees, all of these have so much potential, let them be written by the great authors of our day!

Behold, my childhood
Once a world is built, there’s a lot you can do with it (see chart). A competently directed writing effort could create a vast array of books, films, and stories to flesh out the beloved world already created. Yes, there would be some busts, but that doesn’t mean that the project would fail. I’d propose that such a project set careful guardrails on what times and places authors could play with, but otherwise leave them general freedom. Some authors, given a proven love of the world and competency of writing could be granted greater proximity. Perhaps the prince of Arkenland will visit Narnia and meet Queen Lucy or Shasta and Aravis preside over a tournament.
Perhaps.
What I’d really love to see done: Charn.
There’s so much potential there to tell a set of mature stories of rebellion, of intrigue, of battle. The end of the story is engraved in a circle of thrones, but the beginning is shrouded in mystery. Did the streets run crimson with the blood of genetically engineered space marines? Were there giants? These are questions that can be answered.
The Empire of Charn, I see it. It spans solar systems.