every couple years my mom goes through a bit more of her attic and i get (goody packages) of fabrics ... all cottons, all high quality-quilt shop quality...most from the 40's and 50's the fabrics are just fine... if it were a problem using fabrics from 15 years ago...what would those quilts be like? there are plenty of 100+year old quilts-the old fabric must be ok.
and people search all over for actual period fabrics to use instead of reproductions.