Agreed. However I have seen Mopars without this pin in place. Also as I recall, the shaft and retaining shoes can be merely pulled out of the coupler. That is possible on Bergman coupler, my memory escapes me on a stock coupler.

If using Borgeson steering box and Bergman coupler there is no pin.

In own experience on my Challenger, the inner shaft could move about rather freely with the plastic shaft pin not in place. Also why it had collapsed so easily when I had removed column for refinishing.

This is why I had qualified my statement as "in theory".

Did not wish to think of such unease while driving the car, so pinned the shaft to ensure that it could not move about and possibly find its way out of the coupler.