Yes they are being replaced by WTS. lawyers
I used to think that District Overseers were over the Circuit Overseers like the CO was above the elders. But evidently it was never the case...it was a more elevated position, and the DO did review the CO's performance twice a year, but the CO did not report to the DO. Correct me if I'm wrong.
But it's been a moot point for 4 years now.