Proof that this is indeed the international poster...
There's one for Spain too... curiously uses "Los Muppets" instead of the Spanish name.
I get it now.
The US version, while the Muppets are the focus, also heavily feature the human actors as well. Now, for what ever reason, be it the relative popularity of the actors internationally, or that Disney's marketing them differently overseas (where they probably care more about the characters than the name human stars), there is a clear lack of any reference to Jason and Amy with these international posters.
Though, curiously I was looking for reference to parody it, I noticed something about the international poster of this movie:
For the lack of a better example, this Brazilian Chipmunks poster lacks Jason Lee's look of
derision annoyance
of being in the film of the antics of the boys. plus, they aren't in hip hop boy band gear.
So clearly they market movies differently overseas.