It’sa shame they didn’t utilise a taller aspect ratio for the HP films in IMAX, because they shot on Super 35. Even Azkaban was shot full aperture (open matte). HP 1, 2, 4, and Deathly Hallows Part 2 look beautiful in open matte.
I’m sure that Fantastic Beasts will also be the same boring 2.39:1 on IMAX. To me IMAX is first about the larger aspect ratio, sound is secondary. The name IMAX is an abbreviation of ‘Image Maximum.’ It was built in such a way so as to differentiate it’s look from general cinemascope, flat and 70mm formats. Nowadays, the IMAX brand has diluted.