While Disney did not outright remake any of its theatrical features during Walt's life, Walt had a history of retreading (or outright remaking) a concept to make it bigger and better, or to make use of new technology. The most relevant examples are the several black-and-white animated shorts that were remade in color, like The Ugly Ducking (1931 and 1939) and Orphan's Benefit (1934, 1941) - a shot-for-shot remake. There's a very clear parallel to be drawn to the live-action remakes with regard to reusing strong material but updating it for new technology and/or modern sensibilities.

Though more of a stretch, Walt Disney World is another good example. Walt was interested in E.P.C.O.T, not in making another theme park, but he understood that's how the company would make money to fund the things he really wanted to do. So, he had no problem cloning attractions from Disneyland - a lazy remake, of sorts - to aid in creating a bigger and better version of something the studio had already built with Disneyland.

I'm not presumptuous enough to claim to know what "Walt would have wanted" more than fifty years after his death, but I think there's enough in the studio's actual history to suggest he could have gone either way on the issue. He wasn't necessarily opposed to the studio repeating itself.