I've said it before, but I've recently realized one of the reasons why I RULLY enjoy FTB, possibly moreso than most other Muppet movies, is that there's hardly any fourth-wall breaking, with the exception of Oscar's Grouch Anthem, and Count reading the credits.
The Muppets are known for not just breaking, but DESTROYING the fourth wall, but that's part of their humor, and it DOES work well, especially if you keep in mind Jim's idea that the characters aren't so much characters, but actors who just happen to be puppets, so when they break the fourth wall, and they do quite often, they do so in really clever ways that don't really talk down the audience or insult their intelligence, it really adds to fun and mayhem that the Muppets are all about.
However, for those rare occasions where a Muppet production contains very little to no fourth wall-breaking whatsoever like FTB, or the aforementioned MTM, it's a nice change and a nice treat, and like previously mention, it does allow you to invest more in the story itself as well as the emotion of what the characters are going through, so yeah. Fourth wall-breaking is almost a given in any Muppet production, but it is a nice change of pace when they forgo breaking the fourth wall on occasion.