I discovered this very thing when I first tried cutting the Blu-ray footage around the LaserDisc audio, and the only conclusion I can draw is that for that particular portion of the entr’acte, Disney either used an alternate take for the general release cut, or they had Taylor come back and record a more streamlined version of the “Soundtrack” introduction to slap right over the orchestra b-roll footage. The former seems more plausible, but the funny is that the introduction audio to the Pastoral segment just moments later lines up with the Blu-ray footage perfectly.
A similar sync issue came up during the Bald Mountain/Ave Maria introduction. Not a single… word… synchronized properly. So I had to keep cutting (and in one instance even stretch) words around to achieve a somewhat decent result, and I still wasn’t completely satisfied with it. In addition, when Taylor brings up Ave Maria, he refers to it as “world famous” in the roadshow footage but “immortal” in the general release. That and the aforementioned syncing issues left me to assume that the finale’s interstitial audio used in the general release version was also an alternate take.