I think it's a good thing to have an idea what fabrics are going to be coming out... you can better plan your projects. Most designers tend to carry the same color palette forward to their next collection (at least one time)... so you can often count on being able to use your leftovers and make a project by adding just one or two new fabrics. That's cost-effective!
Personally, I'm thrilled that the fabric manufacturers are getting their new collections posted promptly. It helps me to make good buying decisions, when I can see and consider all the fabric offerings, *before* the sales reps come calling. Otherwise, it's too easy to buy the "wrong stuff".
Oh, that sounds bad. Not that fabric can ever be "wrong"... but if I know that the best snowman line is carried by next week's salesman... then there's no need to buy a less-appealing line from this week's salesman. You get the idea.