The ID of the coupler is internally splined for the drive shaft, it's not a flange affixed to the drive shaft as an inboard has. The crankshaft end is threaded and the coupler is threaded onto the crankshaft, the drive shaft slides into the coupler.
So any misalignment of the drive shaft to the crankshaft will accelerate wear of the splines, perhaps dramatically, depending on how far out. I think you'll see more once you remove the jet pump.
Regardless, if you move the engine you'll need the alignment fixture,, which requires removing the jet pump, so it's best not to move the engine unless you have access to an alignment fixture (they can be rented, or perhaps borrowed).
On a ski of this age, considering things can move around over the years, it's not a bad idea to check the alignment anyway, with the pump removed.