Continuity mistake: When the song about Ebeneezer Scrooge is about to end, just as Ebeneezer is walking down the last lane, the first Muppet you'll see to the left when he has come down the stairs is wearing a red weird hat. Just a second after Scrooge has walked past the lady with the funny hat, when they sing, "If being mean's a way of life you practice and rehearse," you see the same Muppet with the same hat, now standing in front of Scrooge. She had no time to get there between the two shots.
Continuity mistake: When Scrooge is talking with Honeydew and Beaker at the end, the Grapes Tavern sign behind them keeps changing position between shots. (01:14:30)
Continuity mistake: After the penguins ice skate, Gonzo and Rizzo skate, and Rizzo falls inside a barrel. If you look closely, you'll notice that Rizzo falls past the barrel hole.
Answer: The song was originally deleted from the theatrical release, but included on the VHS and widescreen version of the LaserDisc. On the early DVDs, it's included in only the full screen versions. It is not included on the original Blu Ray release because the original master and negative were lost. However they were found and Disney has said the song will be included on future 4K releases.
LorgSkyegon