It depends on whether the mechanical load can hack it.

A 2-pole motor runs at a higher speed. Most loads' torque requirements increase with speed. Power is the product of the torque and the speed. So if the 4 pole motor was running close to its overload trip setting, then the trip will probably operate with the 2-pole one. However, it cannot be seen from here.

I think you need to consider the mechanical side of this. I can't think of any device which will accept a driver of twice the speed and half the torque. Unless it's belt or gear driven, in which case sheaves, belts, and/or gear boxes will have to be replaced.