Ok, now I know what you are talking about. There are two tables there for NE Mutual Aid. The top is the old frequencies used before rebanding. The other table lists the rebanded frequencies and I have picked up traffic in the form of CW ID on 851.30000
Now whether someone else is using the old frequencies I have no idea.
As for your original question, as far as I can tell, the broadcast is in the clear with no encryption. I say this, because as I indicated above, I have picked up CW ID.
Douglas County is using both sets of frequencies, Icalls and Itacs. They have set up temporary repeaters for the non rebanded frequencies. They will remove them once the rebanding process is completed.