West Valley City's monthly meet the Chief meeting tonight (9-12-18) highlighted VECC as a the specialty unit talking about their ops and they was saying that Herriman PD will be dispatched out of VECC starting September 30, 2018. They also said that as of January 1, 2019 all UPD dispatch and call OPS will be moved up to VECC as well. I would start looking for the new comms to start at the end of this month.
I concur with Observer1 Unified will keep their existing TG COMMS on UCA I don't see that changing and as far as Herriman as of 09/14/18 while on shift I still heard Herriman units dispatching on Unified Oquirrh(west) channel so I would assume since the system is going to start going through upgrading for P25 soon I would say that Herriman will continue to dispatch through UPD Oquirrh channel and then as the system upgrades then they will be on their on TG COMMS at that time. It only makes since the transitioning period into P25 shouldn't take more then a year to make happen.