This usually means the structure was built where expansive (clay) or collapsible (sand) soils are known to exist. Combine that with extreme moisture and/or poor drainage and the structure becomes very unstable.
Something as simple as rain run-off from the roof and allowing the water to "pool" can cause your foundation to shift. It doesn't have to be a lot of water to have adverse effects on your home's foundation.
Structures built on back-fill lots are always in danger of weakened foundations because of potential air pockets in the soil and soil composition itself.
Once the home's foundation has been piered the opportunity of movement/settling in the repaired area is almost zero. The same cannot be said about the areas that were not piered, although it is doubtful, since the prime reason for repairing the damaged structure was to stabilize it overall.
Once that is accomplished, further damage to other portions of the foundation's walls is unlikely. Although this may be an oversimplification your home or building is much like a wobbly table caused by an uneven floor.
Once you shore up the section of the wobbly table this corrects it's unevenness. The table will firmly be stabilized. It does not mean, however, that excessive rains or water caused by poor drainage or change in landscaping cannot cause additional soil instability once again.
The cracks will close but to what extent is impossible to predict. Many will close completely and others will not close all the way. In any case, the cracks may be tuck pointed and your wall will look whole, and be whole once again.
Alpha Foundation Specialists' system uses helical piles which screw through the shallow unstable surface soils into the deep stable soils (typically 15' deep or more) which prevents any movement of the foundation. Many contractors simply lift the home and add to the existing footing.
The problem with this solution is as soon as the soils expand or contract the foundation moves with the soils and you are addressing the same problem you were before.