Aslan is Jesus. Why is that not mentioned? C. S. Lewis made that quite explicit, and that’s why many of the fans love it.

If they do cast Meryl Streep as Aslan that will be a direct insult to many of the most devoted fans. That is casting Jesus as a woman. That is an automatic nonstarter for most Christians. It will be dead on arrival, and I think many people would quit their Netflix out of protest.