Anne - classes do not count towards the moratorium. Neither does thread, cutting blades, batting, and other necessary accessories to finish up quilts. And yes, you can do it. You can use stash fabrics for the class.
I'm trying to organize my UFOs and ongoing projects (WIPs?). In doing so yesterday I pulled out all the FQs and piled them on the bed. Yikes what a pile! So I decided to sort the FQs for the Turning 20 pattern, which I've had for years but never used. It is a good pattern for charity quilts as it makes up fast. I ended up with 8 baggies of 12 FQs each for throw quilts. But I still have a tub of FQs left over -- they just didn't go well together. But since FQs tend to breed like rabbits, I'm sure I'll have some matching ones in a few months, or I'll start cutting from yardage.
So... a long winded way to say I'm using stash.