From the 11/15/09 WT study article: "it is heartwarming to know that a large number of such ones [disfellowshipped ones] later return to Jehovah and his congregation...". This is a typical cult phrase, where they use a generic unverifiable statement to prove a point. So, since we're not likely to get an official answer from the WT, how many of the DFd ones in your vicinity has actually been reinstated?
I can recall a total of 7 disfellowshipped persons, out of whom one returned, so that's 14%. There are a huge number of faded persons here, only in our congregation there are at least over 15 who are well and healthy and stopped visiting the KH - they don't seem to care about the Watchtower. As for the article it only mentions the actual DFd ones, so they don't count then.