Knowing Ed, "True Oldies" or another satellite oldies network (such as Westwood 1) would be very unlikely.
The main issue is that the station has to greatly lower power at night. 10 kW days, 2 kW "critical hours", then just 100 watts after sunset. May not be worth paying for evening or nighttime air talent on that signal alone even with the stream.
I've heard it at night on the WATD simulcast, from Quincy/Milton it covers some coastal South Shore towns and the neighborhoods of Boston south of downtown, and it goes north of Boston up the immediate coast to the lower coastal North Shore. The night signal doesn't go inland away from the coast well, though. I hear it where fairly well where I am in east Somerville near Route 93 and the McGrath Highway from Boston, but if I go inland west just a couple miles, say toward Davis Square, it fades out at night.
An FM translator on 101.1 was proposed, maybe to be licensed to Weymouth, but that's held up for some reason, and it won't cover much more ground than the AM night signal, maybe a bit farther southward down the coast, but it will just do so with better audio quality.
I'd suggest automated oldies during those unscheduled hours to keep the format audience for the stream and for nearby local listeners, with options to cut away for local community service programming or brokered programming. I don't know if it could be possible to make an arrangement with Gary James, a former program director of the 1980's oldies 1150 WMEX, Boston who programs the automated oldies WMEX-LPFM in Rochester NH, to simulcast that at night, or if there would be logistical or legal issues with that, have him provide a separate automated oldies music program for it as he does for WGAM/WGHM in NH (the former WKBR and WOTW). Or, Ed's staff could probably create an automated oldies program themselves with their own avails for spots, promos, drop-ins, cutaways for special shows, etc...