Quite often there is an extra fabric kit available for BoMs. Some quilters may wish to use their own selections.
Can be a trade-off for the store but with the fabric kits available I think it is a win/win. Someone like me who has her own color style and plenty of fabric might buy the patterns without the fabric. Someone else might just love the finished project look or the fabric pack and buy the patterns just in order to use the fabric.
But always disappointing to get something other than what we think we are getting. Double check, and good luck!