When are CO's due their new assignments? Is it Sept 2011? Maybe that's when the society is planning to get rid of them.
There could be two reasons to get rid of CO's:
1) To save money
2) To avoid legal liability
In fact those are the two reasons for all of the Society's proceedural changes these days.
But I am not sure if getting rid of CO's would save them money. Do local congregations cover their costs? Or are they a significant cost to the Society as well? As for legal liability, I assume it is much harder for the Society to argue that CO's are free agents, as they do with elders in judicial cases, if they are giving them an allowance.