So far, only emulated versions of PS1, PS2, and PSP games, such as Disney-Pixar's Up, have been rated for the service, according to Gematsu. The rating doesn't refer to WALL-E's PS3 version ...
Disney•Pixar Wall-E has been rated for PS5 and PS4 in Taiwan. This should be an emulation title for the PlayStation Plus Classics Catalog. Unclear whether it'll be the PS2 or PSP version though.