I've known this for a while. Outlets, Saks off 5th/Nordstrom rack/last call/tjmaxx/marshalls are all carrying made-for-off-price-retailer stuff. They do have some legit last season/overstocks, but you have to dig for it through all the lower quality stuff.
Some brands have licensing agreements with tjmaxx and similar stores; the off price retailers get to make and sell branded stuff with the designers labels on them. I'm guessing Michael kors and Cynthia Rowley both have these licensing agreements with tjmaxx because there is so much Michael by Mk on the racks and it's all polyester and a little bit off, and how many basic t-shirts does Cynthia Rowley actually design and yet there are hundreds of them in the racks at tjmaxx every time I go in there. Same with the high-end department stores offprice outlets--licensed goods made of lesser materials that pretty much look like the real deal unless you really know that "brand x" hardly ever uses polyester in their garments or whatever.
A quick way to tell is check the tags. All the labels sewn in the garments look different if they were made for outlet (BR/gap have diamonds on the labels for outlet made goods and etc). The licensed stuff at tjmaxx will have normal looking tags sewn in, but the hang tags will be different. If it's licensed, it generally won't have the MSRP on the hang tags. At the department store outlets, the legit overstock stuff will have the tags from the original department store (Saks 5th Avenue tags on a garment at off 5th) on it but the licensed stuff doesn't usually have them.
I don't do a lot of actual outlet shopping anymore because of the inferior quality. I do still occasionally go to the high-end department store outlets, and I do shop tjmaxx/Marshall's but I'm pretty picky about it these days because I've been burned too many times on a "good deal".