I can't speak for those making the claims back then but I think it was a lot less about it being a generic touch control scheme for a mobile game and more to do with it having a lot of very similar specific design elements. (For example, two side by side dedicated potion buttons).
We will never know for sure though. All we do know, is that Blizzard has partnered with NetEase on this and both games are developed in the same engine using roughly the same control scheme. Though they also do have significant differences such as Crusaders not being locked to isomorphic view like Diablo.