The bit about them measuring gravity or magnetic waves is complete hokum. You can put that hive wherever you want. The hive should be protected from harsh cold winds, and facing the entrance east or south isn't necessary except that morning sunshine warms the hive and helps the girls get out early. I'd worry more about picking a direction that protects the entrance from wind driven rain first. If that happens to east or south, then so be it. Also, bees take 30 to 40 feet to get up to altitude if they fly straight out from the entrance, so if that's an issue (e.g. near a walkway or roadway) face the entrance another direction or face it towards a barrier (fence or barn) so they have to spiral up to altitude.
You are by no means locked into that location just because a crank with a bent wire muttered hocus-pocus. Now that the bees are oriented to it, if you do move it, move it only a few feet at a time, or wait until dusk, then loosely stuff leaves in the entrance and the bees will re-orient in the morning.
(edit, fixed typo)