The idea of Batista returning to WWE isn't without problems.
He turns 49 in January, and hasn't wrestled since leaving the company in 2014, meaning there'd be significant ring rust to shake off. The man's acting career has really taken off in the past few years, too, and it'd be impossible to fit those commitments into WWE's notoriously hefty schedule. Then there's the small fact that his last run was a universally rejected disaster, with fans dumping all over his Royal Rumble win, headlining spot at WrestleMania XXX, and constant presence in the spotlight. Few were disappointed when he left, and it'd take a lot to convince those same people that his return would be a good idea.
Regardless, a Batista comeback makes sense on several levels. Hollywood has made him a bigger star than he was at the time of his departure, so he'd be a considerable draw, and WWE could use his legacy and reputation to put younger stars over. He'd also benefit from the lack of Daniel Bryan, whose Rumble relegation was the driving force behind Batista's rejection.
In terms of name value, Batista is comfortably the biggest return WWE could deliver in 2018, and it may just be right around the corner.