I think the best way to answer this question is to focus on themes of "The Catcher in Rye."
One theme from the novel is alienation. Specifically alienation of a youth, but alienation could apply to anybody. I believe that alienation is just as present in today's culture as it was when Salinger wrote the book. As a teacher, I see alienation from week to week. It's unfortunate, but it is true. Not everybody feels like they fit in all of the time. I have no solution for it. I can't even place a cause for it in all situations.
Another theme of the book is phoniness. Holden can't stand it. I mean, he really can't stand phonies.
"One of the biggest reasons I left Elkton Hills was because I was surrounded by phonies. That's all. They were coming in the goddamn window."
If that's how Holden felt about it in 1950, I can't imagine what he would have to say about it now. Phoniness is practically encouraged today with online avatars and personas. Social media seems to always give the impression that everything is awesome all of the time. It's a false image of reality more often than not because it's only reflecting certain things. Holden would see right through it, and it would make him unbelievably upset.
One more. Relationships and sexuality. Over the course of Holden's weekend, it is clear to the reader that Holden is searching for some kind of relationship. Not necessarily sexual, although that is addressed too. But the phone booth scene points at his desire to connect with someone. He just can't figure out exactly how to do that though, so he keeps convincing himself to not call. He's searching for some kind of personal contact with people, and he just can't find it. This ties in with isolation, but I do believe that finding emotional and physical intimacy with someone is a huge motif in today's society. If you don't believe me, watch an episode of "The Bachelor."