It depends on the engine coils. With 4 poles you cannot predict the spinning direction. Any greater number of poles will enforce a spinning direction.
So in a way you're off, AC motors *do* spin in one direction (think of AC fans...) because generally they have 6 or 8 (or more..) coils.
But, in this very case, i suspect the low-cost pump features a 4 pole engine (coils are expensive) so the direction cannot be fixed - so you're right
