Seems to be the whole premise is that Miyagi and Chan's character knew each other, Chan did kung-fu, Miyagi did karate. Chan has a student, trying to become the best, and Chan asks Laruso to train his student in Miyagi karate, bringing back the connection that Chan had with Miyagi, 2 branches, same root.
Its also bringing the 2 branches of American Cinematic Martial Arts, Karate Kid (being the 80s, americanized karate movies) and Jackie Chan (revered chinese martial artist, who also did a LOT of american comedic martial art movies).
And both too to be passing the mantle down to this new kid actor, who we will probably see as the successor in american films.
all for it. love me some karate kid. love me some jackie chan.