I confirm the observation of Phase 1 voice on the new system as well. Yesterday while I was returning from a trip, I drove through DE on US 301, and the NCC site was carrying Phase 1 audio on certain talkgroups.
Also to note is a Peer Site 17 on the P25 800 MHz system. NCC was showing Peer Sites 12 and 17. I'm thinking that it might be a supplement to the Wilmington area, but I was unable to locate a specific site location, as I was on an assignment for work and unable to stop. I got the signal strong for a brief section near the Wilmington Airport, and then it started to fade away as I went over the Delaware Memorial bridge. The CC was 853.0875. The NAC was 680 but I wasn't able to get anything else. I literally got it for about 5 seconds and then disappeared so the info might be subject to change.