I believe Uniden ignores encryption if you're actually scanning the frequency normally, however if you force it to scan those frequencies as Analog audio type (not All or Digital), it should let anything through. Perhaps you could do that and enable attenuation on them so that you'd only pick up anything strong/nearby.
Interesting mystery. I see nothing in any of their recent village minutes to indicate that they would've gone to another system like MRRS. Looks like that resolution to purchase the UHF APX radios passed last year, and another resolution over the summer to renew the maintenance contract with Goosetown.