I think you're leaving out a third (and probably the biggest) group: people who've never seen CBJ before or barely remember specifics about the show from previous visits.
As much as Disney is pressured to honor its history and legacy, it must also create a theme park experience entertaining to modern audiences and worthy of the nearly $100 admission ticket.
As I've said earlier in this thread, there is a lot to like about the original CBJ. But it was painfully slow-paced by 2012 standards (and that's NOT because of short attention spans! It's because other types of entertainment have raised the bar on what audiences expect in terms of pacing.)
Disney (and any other entertainment provider) must consider what an attraction/show would look like if it opened up brand new today. Haunted Mansion and Pirates have easily held up over the years. Hall of Presidents needed a major facelift to keep it fresh and modern. We can all agree that the original CBJ would never be built as-is in 2012.
So Disney had a choice: close CBJ, create a new show from scratch, or try to tighten up and improve the pacing of the original show.
They were probably wise to avoid gambling on an "Under New Management" complete re-do. That left Disney with the option of pulling out their scissors and cutting out the slow-paced parts.
And I think, for the most part, Disney succeeded with that task.
Those of us who have the old show memorized can hear and feel the edits when we play it back in our minds. But I think most people unfamiliar with the original will never notice things have been cut or are missing.
Disney cut out the same unnecessary dialogue that I would have cut out if I was in charge of the rehab. And I don't mind most of the abbreviated songs.
I think a majority of park guests will view this show as a short, pleasant experience, with much fewer people sitting in the theater during those long stretches of dialogue thinking "Gee, this thing is outdated".
(** It looks like the opening with Max, Melvin, and Biff was accidentally cut short on the WDWMagic video -- there is an obvious edit on the video-- so I'm withholding judgement on that until I see the full opening. Other than that, there was really only one odd edit with Henry's laugh just before the Sun Bonnets. It appears they needed a transition between two pieces of music, and they may have made the wrong choice there.)
