Reality is this is likely about as damaging to society as Y2K was. If the poles reverse, compasses will point to the new magnetic pole and that really is about all that will happen. Since we generally navigate through GPS now it won't impact much and when we do need to navigate using the pole, maps will have to be adjusted to the magnetic pole, not to true North (But since the Magnetic pole has never been at true North it probably won't matter at all since a compass really just ensures you are moving in a constant direction and it still would do that.)

Any of the really catastrophic consequences of the poles shifting would be visible in geological records like in Arctic ice cores. Since the poles have shifted about 100 times in the last 20 million years or so, we definitely could find a record of major problems. Suffice to say our computers and navigation systems can be adjusted as it changes so I expect on the scale of things we would see more likely no impact than any impact.

It is what I expect at least.