I started a historical replay in 1919. I set ratings to be based on a 3 year average, and changed these settings, so a player like Joe Jackson can continue past his IRL ban.
It is now 1932.
What has seemed to happen is that players who have careers cut short never seem to regress or retire. I should've taken a screenshot, but I just had to manually retire around 30 players, all 42+ years old, still in the prime of their careers. I should've taken a screenshot of the active players list before I did this, but here's one guy I manually retired, cruising along at 47:
And here's his scouting history, never regressing at all:
