Retrograding potatoes means raising them to a temperature where the starches are liberated from their initial structural networks, and then allowed to cool so that they recrystallize in a stabler network. Autoretrogradation means having a process that does this without needing human intervention somewhere in the middle.
An example of something you can do with a retrograded potato is tossing it into a stand mixer and beating the hell out of it without them turning gluey, which happens the starches get mechanically freed up and then crosslink.