I wash everything because of the chemicals. FQ go in a mesh bag. If there is a little fraying, I feel it is a necessary evil.
I worked in a clothing store for several years. When we opened a box of imported garments the odor was awful. We would hang them outside behind the store to air out or the whole store would stink. They not only treated fabrics with sizing, but imported items were treated with insecticides or we would open a box of bugs. I am assuming that since almost all fabric is imported that quilt fabric is the same.