I would say most of the time, yes. They still might be your crush if you are rejected though. You also might have a work crush on someone, but know it's not real or you're already in a relationship. Then you wouldn't ask them out for other reasons than being afraid. I probably broke this down too much.
I'm a 32 yo millenial and the first time i read "my crush" in a sentence was in a teen magazine when I was 12 yeard old, and from context, it definitely meant "person I have a crush on"