If you use a magnetic compass to figure out your initial disk azimuth, you will need to make adjustments ... but a declination chart is usually sufficient as the movement of the poles is rather slow (see
Magnetic Declination (Variation) Home ).
An in-motion dish just uses signal strength sampling to correct its aiming so, after it gets set up, it should compensate for all the earth and pole movements, I'd think.
Reports are that Japan moved about 8 feet so far. That is different from an axis shift (See
The Earth’s axis has shifted 10 cm - Earth-issues.com | Earth-issues.com) which is different from magnetic pole wandering.
The axis shift thing is kinda' like what you do when you put weights on your wheel to balance its rotation. The weights on the wheel being moved around to change the center of rotation of the wheel (its axis) is like what is happening with Japan moving 8 feet.
If you do plan an RV trip in Japan, keep in mind that the map in your nav system might be off by 8 feet.
It is going to be interesting to see all the 'woe is me' catastrophic FUD mongers for the next few months. I already see the climate catastrophe and nuclear china syndrome (the antipode is probably something like south georgia or the sandwich islands or the abyss off Uruguay for Japan, though) types in full throat.
Meanwhile, prayers for those folks in Northern Japan. what a horror they face.