Does this apply to all genres or just highly produced popular music? I would not be surprised if I failed to detect an AI song as background in a television commercial, but it is difficult to imagine that anyone could fail to pick out an AI impersonation were you to slip one in to a record like 'João Voz e Violão.'
It really depends on the style, yes. You could probably slip one into any modern pop/dance/club/EDM album and no one would know as long as the vocals sounds like the performer. For styles which are very unique with that sort of imperfect human touch that makes music so enjoyable, it would likely be obvious, at least at the moment.