I originally thought this too, but after reading through the PR again, I understand the situation to be that they were anticipating more dilution from the remaining C shares that weren't eliminated.  They said the eliminated C shares would "mitigate" or lessen the amount of potential dilution.  So the share buy-back seems to me, to try and keep the O/S near the same neighborhood they're in, as opposed to reducing from the current levels.  Someone correct me if Im wrong..