I believe the listings on ShopDisney.com specifically said Stacey Aoyama. But Eric Tan has done a bunch of stuff for them in the past as well.
They worked together as a team on the Epcot posters. If you look them up on Instagram (Eric, Stacey), you can see them both posting pics and talking about the posters. Stacey most recently mentions that the first poster she worked on was for Japan.