It's legitimately the perfect guest star. She is
A) at the current peak of her incredible relevance and popularity, especially among younger demographics that would otherwise not be interested in Muppets content.
B) separated enough from the Disney company to where this doesn't feel like naked, shameless cross-promotion.
C) goofy and irreverant enough to play along well with The Muppets.
This is unironically the biggest opportunity for The Muppets to jump back into relevance since 2011. It's Disney's to lose.