Please be careful to distinguish the steady process of magnetic variation (the direction to magnetic north slowly creeps sideways by a fraction of a degree every year, in a predictable but globally variable manner - all serious navigation maps state the date of publication, the direction of due north (magnetic declination) and the rate of change each year - magnetic variation. To find accurate north, you calculate the years since the map was published, and add the variation times the years to the declination.

The process is NOT uniform , as the article points out, but is more or less predictable.

A reversal of the Geomagnetic polarity happens every few hundreds of thousands or millions of years. This is well-recorded in the geologic record.

The phrase "Pole Shift" is an anomalist's phrase for sudden and catastrophic shifts of the earth's surface relative to the poles, rather than the poles steadily moving. You should avoid using it in this forum unless you qualify the usage as I have done.