It's bad news for navigation I suppose, but we have almost no idea if it's bad news for humans. Species have seemingly lived through many polar reversals with no signs of mass extinctions, so probably not too much to worry about.

The polar reversals appear to happen slow also, so we'd probably have plenty of time to adapt.

I'd say the most likely catastrophize is the field lowers enough some electronics get friend and some navigation gets screwed up, but I don't think it happens fast so it would probably be more like a trickle of problems, not an avalanche of problems.