Without the Moon, the tilt of Earth's spin axis would vary chaotically between 0 and 85 degrees.Really... I thought pole shift would never, ever work because the Earth is an oblate spheroid.
I would just 'reshape' itself like it did at the end of the Ice Age when the weight of the ice was redistributed around the world. Look for gawdawful earthquakes, volcanos, tsunamis, land suddenly sinking and rising and etc.