Too bad no one ever called them "Star Destroyers" in ANH.
Are you sure? I seem to remember Han saying "Star Destroyer" when the Falcon was fleeing Tatooine.
And it's entirely possible that "Alert my Star Destroyer to prepare for my arrival" was taken from a Tantive IV outtake that wasn't used.
I hate the line in its current ESB SE spot, but I've never thought it sounded like anyone but James Earl Jones. I don't know where people are getting that idea.