The problem is, there WAS no place to put Piggy as far as the story go to begin with. Jerry managed to find a way to add her in, gender swapping a character and changing the character's role. I agree her role was kinda... well... contractually obligated in the film. Not her best one, but I'm starting to dislike her role in MFS more.i did not like this one. it's criminal how tiny a part piggy has, and kermit too for that matter.
That's the thing about MTI over MCC... Jerry managed to warp the source material to fit as many Muppets as possible in it. MCC was more rigid, much closer to the story... and that isn't really a great thing. Seems like with MCC, the only Muppety alterations were cut and paste in front of character roles... this one was put in a blender with extra Muppet flavors and it comes out a much more fun movie overall.