Q,
As I speculated in a previous post, the movement seemed quite as expected.
There is a backlog of 10-11k cases for EB3-ROW due to the retrogression of dates earlier in the year. There aren't enough visas available to cover that demand and move the COD back to Oct 12 in a single month.
It's very similar to the way CO brought EB2-ROW back to Current at the beginning of FY2013 after they had retrogressed for the last quarter of FY2012.