Will your goldfish die if it has a swimbladder disorder?

It all depends on what is causing the problem, it could be because of an infection, constipation, deformity, or egg impaction. Before you assume this condition is untreatable try doing some large 50-75% water changes, feed the fish lots of veggies, or you could try, if you suspect an infection, feeding a medicated food (available at the link posted below) or, if you suspect an egg impaction, attempt to hand spawn the goldfish so it can release it's eggs which are causing the problem.