A lot of times when I use fleece it will just be two layers since fleece is thick and warm. I still call this a quilt. A lot of people will just a cotton back and top and call it a summer quilt.
I think the only time the definition is important is when you are entering a quilt show/contest then you just abide by their rules - the rest of the time, if you made it, you decide. Just my 3 cents worth - usually I only give 2 cents worth!