Son had soft palate repair roughly 2 mos ago, stitches have dis., but very sml. Hole remains, could this heal on it's own?

Follow up. Well, it may not be functionally significant. This means that the most important part of the repair is whether the muscles are functioning properly and the soft palate hits the back of the pharynx. This may be the situation and you could leave the fistula untreated. So it may not be a big deal. But it does need to be followed with speech therapy and ent.
It is possible. One of the most common potential problems after palate repair is a "fistula" or small opening in the repair. If it is small enough and early, it is possble that it may heal spoontaneously, however, sometimes a second surgery is indicated. You should follow up with your plastic surgeon to discuss the options.