From what I've heard... They've actually tried to give Wrecking Ball skins recently, but with the Overwatch engine being so old giving him one more skin would just break the game, being unplayable...
Thankfully Wrecking Baby being added will fix this issue in Season 5.
The truth is that Ryuji wanted to be in Fortnite, but that fucking scumbag was asking for too much in royalties to use his likeness. We almost considered creating an Android version of him before ultimately deciding that even that would be more than he deserved.