I really don't think there should be much debate that J. D. Salinger intended the name of his male character Zooey to rhyme with
Huey,
Dewey, and
Louie, and not be pronounced the same as
Zoe.
In the short stories where
Franny and Zooey are sister and brother, they have an older sister named
Beatrice whose nickname is Boo Boo. I think it's highly unlikely that Salinger wanted that pronounced as "Bobo". So it's pretty clear to me that he also would have wanted Zooey pronounced as if it contained the word "zoo".
I think the fact that Zooey Deschanel pronounces her name like
Zoe or
Zoey is rather unfortunate.