Someone noted the other day that the locos allocated for conversion to 66/6s had been moved out of that pool, for whatever reason. Could be true that the 60s are coming back, or (more likely IMO) could just be someone speculating based on this.
They were using two HTE 66s daily for the Portbury steel workings but that traffic is (nominally) back with GBRF now, so maybe they don’t need any more conversions at the moment.