Seems like your guess was right. Also, I did hear one or two transmissions on the analog system that were NOT mirrored on the 2008 TG, but they were very brief and seemed to be a supervisor based on the order given (all units clear, unless this meant all units clear of the old system). This was the last heard analog transmission on the analog system thus far (as of 1411 CST).
Also, 460.075 and 460.125 appear to be in use with the new P25 system for passing voice/data, but I am suspicious of 460.075 as the SDS200 shows a frequency of 460.0875 when the analog is showing 460.075. 460.125 matches on the SDS200 and the analog (of course the analog is the usual P25 noise). Maybe someone can investigate the reason for the offset (not sure of channel widths for P25P2, but it might be 460.0875's bandwidth overlaps the old 460.075's analog assignment).