To be honest, I don't know if crinklies are a no-no or not. I like how my quilts look when they come off the frame, so it's not an issue for me - crinkles hide the hand quilting design.
Being clean and hanging relatively flat and straight do seem to be important, and if you can accomplish this by washing, then it's a good thing to do. I find that quilts that I wash and dry tend to uncrinkle themselves over time, anyway.
Janet