They've got WoW, Overwatch and even Lost Vikings as family friendly IPs and there's countless things they could do on mobile with those two.
Hell, they even got a children's book set within the Warcraft universe called Traveler, they could've adapted that into a family friendly mobile game.
The whole book series so far is canon, the main character experiences events, encounters important characters and deals with some typical baddies. Sounds like prime material for a game with purchasable episodic content, season passes and etc. I bet Blizzard could fill in the niche left behind by Telltale Game's collapse and release their own series of point-and-click adventure games set within a few of their IPs.
Instead we get Diablo: Immortal...