Since the ps pump is connected through a flexable link (the belt) it should have no effect on crankshaft fore and aft movement.

The problem I have with your original question is that the bearing is a much softer material than the crank shaft. If there were wear between these two, it should be the bearing that sacrifices itself to not harm the shaft. Are you describing an actual observed condition at the thrust bearing surface, or are you speculating because you've measured excessive end play, but haven't done disassembly yet?