As Entwistle shared with the outlet, he definitely thinks Jaden Smith’s The Karate Kid character is still absolutely canon and out there somewhere in the world of Karate Kid: Legends. It seems like perhaps he wasn’t deemed necessary to the story of Ben Wang’s Li Fong and therefore is not in this new movie.

Legends Karate Kid: Legends marked the franchise's big return to theaters after the major revival that the series saw during Netflix