Muppet Wizard of Oz wasn't terribly good, IMO. The notion of a modern Dorothy living in a trailer park, working with her Aunt and Uncle in a diner, and wishing to escape to a better life, that was good. Unfortunately, the Muppets themselves were somewhat wasted in this effort. The jokes weren't up to par, the songs were forgettable...oh, wait, that might be a plus, come to think of it.
The real problem was in superimposing the Muppets, with their own characteristics, upon the familiar characters of Oz. They didn't mesh very well. The familiar Muppet zaniness, which is quite modern, was not well served by the morality of Oz, which is more American Victorian in style; nor was Oz well served by the modernizing influence of the Muppets; Miss Piggy as a motorcycle-riding and leathered Wicked Witch was jarringly out of place.
It's been long enough between major projects that the Muppets can stand a good shot in the arm, an updating. This film didn't do it.