It seems that due to the thinning ranks of "capable" Italians and competition from other ethnic gangs, the "rules" have become a bit relaxed.
It's said that some families will now make an exception if the "recruit" is Italian on his father's side, whereas way back when, one had to be 100% Italian.
The best example would probably be John Gotti Jr, whose mother is Russian-Jewish. It is now rumored that due to the defections and legal troubles of the last decade, the old rules are going to be re-enforced.