Yes, Shusui is a national treasure and Momonosuke is the future Shogun of Wano as well as the son of the man who saved its citizens years ago. His grandfather was the Shogun before him and Momonosuke himself is about to become a hero by preventing Onigashima from destroying the Flower Capital. If he's not worthy of Shusui with such a curriculum then I don't know what it would take to deserve it.
