dumber than a box of hair said:
No, WILD's daytime status is not hurting its sale one bit. WILD's license conditions are a matter of public record. Anyone can look them up on the 'net and see that they're a daytimer. It's no secret.
It's also a matter of record that Baltimore sunrise occurs as much as 1/2 hour AFTER Boston sunrise (Baltimore is WEST as well as south of Boston), so during the first 15 to 30 minutes after it signs on, WILD is technically subject to WBAL's full nighttime skywave signal. In practice, as sunrise approaches, skywave propagation diminishes on the AM band, so the effect is not as serious as it would be at, say, 2:00AM if WILD were on the air at that time. In addition, the FCC has designated the two hours after local sunrise and the two hours before local sunset as "critical hours" (CH). WILD must reduce its power from the almost 5 kW that it uses at midday to 1900W during CH. The effect is obviously symmetrical. That is, WBAL's daytime-skywave interferes more with WILD during CH for two reasons; the interfering signal from WBAL is stronger than it is at midday (when it is assumed to be entirely groundwave and thus very, very weak in the Boston area) AND WILD is uses lower power during CH than it does at midday.
All this is well understood and completely legal. As a Class A AM that predates the Class D WILD, WBAL has the rules on its side. Now, if WILD were ever purchased by someone who had big bucks and wanted to spend them on upgrading the daytime-only station, WILD could probably move next door to the WEZE site, where it could install a directional antenna (DA) and get a major power increase (maybe even to 50 kW), BUT it would still have different operating parameters during CH (as compared to midday), which would limit radiation to the west (despite the higher power, maybe even moreso than at present, thanks to the FCC's arcane "ratchet rule"). More importantly, WILD would have to remain a daytimer, although the DA would allow it to use higher--albeit still very low--power during the 15 to 30 minutes between Boston sunset and Baltimore sunset. AND since, as I understand it, WILD holds, but does not use (because of the very low power it is allowed and the very strong interference from WBAL), severely limited pre-sunrise authority (PSRA), the new owners might find that it made some sense to use the PSRA.