I don't think it's fair or accurate to call The Muppets a failed franchise - they've led numerous successful films and television series and are undeniably iconic. You could argue more recent efforts to revive The Muppets are commercial or critical failures, depending on the project.
In this case, it's pretty clear that Disney anticipated massive backlash to the shuttering of Muppet Vision 3D and wanted to finally ditch the Aerosmith branding for Rock 'n' Rollercoaster. Two birds, one stone.
Saw a photoshop that positioned the Statler and Waldorf animatronics atop the launch tunnel so that they can heckle guests prior to the ride starting. It's a fantastic idea, so I'm sure it won't happen.