And I thought this was about an older model fielding some grounders at SS
Generally, players do lose range as they age. Center fielders move to corners, middle infielders to the IF corners, everyone moves to 1B and if you suck too much even for 1B, you become a DH.
Look for example at McCutchen as a player losing defensive capability rapidly.
However, if your question is not about aging in general, but if the OOTP model is specifically accurate, it's beyond me.