I tried to verify who makes Kirkland stuff.
About 2-3 years ago, they made a change in the style and quality. Apparently, the jeans no longer resemble Levis as closely as the previous ones did.
At what Costco sells them for, I can't see Levi making them. Sometimes Costco buys warehouses of stock or material, then rebrands or uses the material to have their products produced by other-than-name-brand makers.
In order for Costco to rename a name-brand item as Kirkland, there has to be materially substantive differences, or they risk lawsuits. I know they had a falling out with Sony in the TV department. From the looks of it, Samsung isn't playing well with them anymore either.
Basically, unless you can find factual information on who really makes their jeans, don't believe everything you read on the Internet. They could be buying the Egyptian cotton, fasteners and thread from the same suppliers as Levi and having the same factories in Mexico run them on the same machines with the same workers as Levi uses. That doesn't make them Levis..