Well if the 2nd reaction was denoted as an equilbrium then Le Chatelier's principle would apply and thus the second reaction would tend to shift to the left due to the increase in bisulfite ion concentraion. At this point, the situation becomes slightly tricky - not only are you increasing the bisulfite ion conc, but you're also reducing the proton concentration in the solution - thus, depending on the amount of H+ ion lost and [HSO3]1minus ion gained, the first reaction will either shift to the right or to the left - it's hard to say with Kc's and concentrations. So, you may form sulfur dioxide and you might not, as well. I have a feeling that the 2nd reaction was intentionally denoted as one that goes completely to the right in order to avoid this confusion.