Correct, and some go even higher, to 5%. It's about what flavor you want and how much you want to control affinage. More salt, of course, means slower rate of blue development. You also have to watch the blue strain salt sensitivity. Some blues will die off at 2.2-2.5%, and some will make it to 6%.
Beyond that, it's about what taste you want and how salty. On average, blues wind up around 2.0-2.5%. 1.5% is ultra low, perhaps for a direct curd salted like a stilton.