Yes. He named it after his sled.
He, of course, was Charles Foster Kane, the infamous publisher of the New York Inquirer and other bastions of yellow journalism. No one really knows why he did this. Why would an American newspaperman buy a large property in Australia (which he never visited), why would he name it after his sled when it was a particularly poor choice of location for sledding (it hasn’t snowed in Rosebud since the last ice age ended. If it had been his surfboard, that might make sense), and why did the name, against all logic and reason, stick?
Perhaps, like the sled it shared a name with, the area symbolised lost innocence to Kane, although since his childhood was notably lacking in visits to the beach, presumably not his own lost innocence (or at least, not his childhood innocence. His honeymoon, after all, was spent at a beach).
Suburbs near Rosebud: