I think you may have misinterpreted something somewhere. If I recall correctly, what generally gets said about punished players reforming goes something like this:
- The majority of players who get punished once reform and never get punished again.
- The majority of those who get punished twice reform and never get punished a third time.
- The (now small) majority of those who get punished three times reform and never get punished a fourth time.
And the number continues to shrink further on.
I don't ever recall anyone saying anything about "the majority of players who are punished with a permaban are reformed" - so, if you have a link to a boards post where a Rioter said that, I would be very, very interested.