The technology behind the hologram isn't the point. The fact that the "star" being promoted is a fictional character, not a pseudonym or nom-de-plum like the Gorillaz, is what find interesting.
For decades producers and labels have created the act before knowing who the star would be. The Monkees was the first well known example of that, followed by The Archies and others. Today most of the short lived pop acts are nothing more than a good producer, song-writer and investors making a person into a start and all they do is puppet what they are told.
This, however, is different. It is a realization that the act could be inherently fake and still sell records and fill concert halls.