That's correct.
Keep in mind that the study was funded by Gelita, the manufactures of Fortibone. If they were to compare hydrolyzed collagen peptides to their product, and they were equally effective, there would be no financial advantage for them.
Unfortunately, no research has even been done comparing hydrolyzed collagen peptides to placebo. Because it's not proprietary, it would be difficult to get anyone to fund such a study. All we have to go by is the study on Fortibone, and don't know how other collagen on the market compares.