Jon Favreau: Luke Skywalker's The Mandalorian cameo wasn't pre-planned from the beginning

Indiewire

“No,” Favreau said in an interview with the Writers Guild of America. “The story unfolded as I wrote it. The Mandalorian inherits a great deal from existing Star Wars stories, and when I write, that context is always a consideration. It became clear that, within the established continuity, certain things were likely to transpire.”