Yes it is true - that most of the American Whisky you see on the shelves comes from about 3 distilleries - contract distilling. Give them a recipe and money and they give you barrels. You make up a name and put it on the shelves. It takes a lot of research to find out where it comes from. One of the reasons I like single malt - Bowmore = Bowmore.
A lot of High west these days is pretty legit, Dave had to buy casks from various places to get off the ground, but makes a lot of it now. But it is easy to supplement.