I think rather than wipe the slate clean and start over Disney will continue to release merchandise related to the PT, but also focus more on the OT and new trilogy and just keep the PT at enough of a distance to not be embarassed by them, but still make money.
Yep, I think more and more as the years go by people will just look back at the PT as an amusing novelty that isn't worth getting worked about and will just be a reflection of where the George Lucas and the film industry (with it's conversion to digital backgrounds and film itself) were at the time. Obviously they won't be *good* reflections of the time (as opposed to say the LOTR trilogy) but they are what they are.
The Holiday Special was this big abomination for so many years but every once in a while you'll see a bone thrown to it like "Animated Debut Boba Fett" figures, the cartoon making an appearance on the blu-rays, and so on. So as you said, acknowledge that it "happened" every so often with various blu-ray and merchandise releases but don't focus too much on it.
And like or hate the PT it really has made a stamp on culture, or at least SW culture. Darth Maul alone is an icon, no way would Disney undo him or replace Ray Park with another live-action version of the character in a remake.