I think I see your point. Whatever I replace the NaOH with will also need to be replaced later by the water. And if the buffer salt binds just as tightly to the column as the NaOH, then there's no advantage to rinsing with salt first. I was assuming that the NaOH is binding very tightly, but somebody pointed out to me that it binds more weakly than most salts would.
So maybe I should be asking about the importance of removing the NaOH completely. Would residual OH- still bound to the column (quaternized polyethyleneimine or quaternary ammonium ligand) due to a low rinse volume cause any damage over time? And would the 20% ethanol that is added for storage pull any residual OH- off of the column since they are both polar?