Honestly there are a ton of games without Ganon and Ganon/Ganondorf don't exist in the past, hell Demise barely exists and I doubt he was the first evil. We don't need to go to the future to see a Hyrule without Ganon and the Wind Waker world basically shows us where the series would be heading without him. Skyward Sword barely answered anything, it created new question and while I don't believe another prequel will answer everything, it made me realize that I want to know how Link got roped into all of this nonsense. The future is simply going to be Link facing off against Ganon, Ganondorf, Vaati, or some new demon, hell even Link Between Worlds couldn't get us beyond Ganon and the whole Triforce nonsense so I can't agree it showed us a promising future that hasn't been shown to us before in many of the various non-Ganon games in the series.
I want to know where Link comes into all of this, that's the lingering question, hell I want to know what Hyrule was like before it was nearly destroyed and had to be reborn. To me these are more intriguing questions than what happens next cause the whole Legend of Zelda wraps around the enternal conflict between Link, Zelda, Ganon, and the fight over the Triforce, I don't think they will be able to really insert a new threat after Ganon besides Vaati or by making a prequel to set up another evil to awaken.