Users are frequently confused if there are existing AcoustIDs that match a file's fingerprint, but the AcoustIDs are not linked to any recording. Users expect the AcoustID tag still to be filled, even if Picard failed to find a recording linked to this AcoustID.

Having the ID can also help the user to identify more details about the file, e.g. by looking up the AcoustID online they might be able to identify the file and then manually match it to a proper MB recording.