Club soda is usually just carbonated water, and the carbon dioxide will be quickly driven by heating. If this recipe came from China instead of Toronto, I'd postulate that the club soda was used because the water was purified, but I think tap water is drinkable in Toronto. Looking at the recipe, blanching with plain water would produce the same end result.
I'd be more concerned that pork belly is really the cut of meat used. The recipe calls for pork belly with skin and bones. In my experience, pork belly doesn't have bones. This sounds more like a cut like what is sold in my neighborhood as uncut country-style ribs.