The reason people get confused about Motorola systems is that they forget that there is more than one kind of Motorola system. For the older type 1 (they should rip it anyway) and the type II systems, SOME frequencies will not track properly. The frequencies below 854 (about) were not originally trunking frequencies, so they were not in the plan when trunking channel numbers for the radios and scanners were assigned. So if a system uses NPSPAC channels (approx. 866-869 – moves to approx. 851-854) and is a Moto. type I or II, your scanner will not track any more (unless updated).
For the new full P25 trunking systems, the frequencies are calculated from a base frequency. Currently DTR already uses 851.00625 as the base frequency and the P25 standard uses a simple formula to calculate the actual frequency used. This is the lowest frequency available in the new NPSPAC band. So the current frequencies are already calculated from this base frequency. Time will tell, but I would argue that no update should be required for DTR or any other full P25 (9600 bps control) system. If it is required it's because the scanner manufacturers did something wrong.
There are issues of bandwidth. Currently the 851-854 band is not technically used with 12.5 KHz channels like it will be. But any decent radio and scanner made in the last several years already uses 12.5 KHz (or even 6.25 KHz) steps. The Pro-96 does.
