I’ve read the same thing, and I agree there’s some truth to it. I think Salinger is coarser then Fitzgerald but equally angst-ridden. And his style is sort of a compromise between Fitzgerald’s eloquence and Hemingway’s pithiness.
After reading A Moveable Feast, in which Hemingway raved about Fitzgerald, I read Gatsby, and I could see why Hemingway made such a fuss.