Most people don't have issues after a while.
The article you've linked is written by a company selling the product.
I have no idea if there are many people without a gallbladder needing those bile salts, but I tend to distrust any seller of a product when they try to convince me I absolutely need their product.
Quite a lot of my friends and family have had their gallbladder removed, and none of them have had problems with digestion after the first few weeks.
Without a gallbladder, you still produce bile, the only difference is that it gets released in a steady trickle instead of the bladder pushing out extra in reaction to a meal. So I'm rather puzzled as to how a gallbladder removal would lead to a deficiency. Mind, I'm not saying it's impossible, I don't know a lot about it, but I'd expect doctors would tell patients about needing to supplement if it happened often, especially because it's such a common procedure.