They can do OTA matching on Major-Minor or RF-Minor, and about 2 years ago they reintroduced the ability to rescan for channels not in the database to Hx2x's and Genies.
The OTA database was frozen in time after the Gracenote/TMSIDs hit the magic 65535 (0xffff) value. A few years ago they started an expansion market by market where they used the gaps to gave the ones with TMSIDs higher than 65535 fake values, but the result is the stations with real TMSID's below 65535 are stuck in their 2010 state, while those with fake ones are passing along RF, Callsign, network and virtual number updates as Gracenote makes them.
i.e.2 weeks ago Philly launched ATSC 3.0 with WPSG's RF 33 as the host. CBS was one of the last broadcast groups to add subchannels, so only 57.1 WPSGDT (34628) has a TMSID below 65535, their subchannels have real TMSIDs in the 100000+ range, so they got RF number updates to reflect their new ATSC 1.0 hosts. Even though WPSGDT still says their pre-repack RF 32, I was able to rerun the antenna setup which automatically mapped 57.1 WPSGDT to its new ATSC 1.0 host KYW's RF 30. WPSG didn't add 57.5 until after the expansion hit Philly so it didn't make the cut, but that shows up via WPVI's RF 6 signal with its PSIP label "CIRCLE" and generic "Regular Schedule" listings.
