The magnificent Troy Baker is no longer voicing Kanji anymore because of some reasons -- Naoto's mystery voice actress is uncertain, I'm not that big on her new voice, it pales in comparison to the old one. Margaret's old voice was perfect, but she was replaced because her schedule didn't line up with the casting (family matters etc). Ken's new voice is probably an improvement if anything -- Him and Fuuka are only ones from the P3 cast who've been recasted.
Kanji's new voice actor is Discount Baker, aka Matt Mercer, he was pretty terrible in the anime but alright in Ultimax.. still not the same as Troy.
The worst of the worst is Igor's new voice which I hope isn't permanent for P5 as well -- Bring back Dan Woren damnit, who also happened to be the voice of Ikutsuki which is rather quiant in this case.
It's not like it's the first time it's happened. Teddie and Chie having new voices since Persona 4 Arena etc. Miss the old Teddie but oh well
It's good that Travis Willingham still plays that particular Velvet Room attendant in Ultimax at least.