Record labels have been doing similar things since the 1950s, building musical acts on-demand by combining skilled, anonymous "session musicians" with an attractive, marketable image or performers that fit the current trend. The most famous example from the 1960s is the Monkees, but this dynamic played a huge part in the development of a surprising number of famous pop bands and musical personalities. Massive public backlash against the perceived inauthenticity of this approach caused record labels to be much more cautious from the 1970s onward, but it's never gone away. Spotify's main "sin" here seems to be that they aren't as skilled as the big labels in manufacturing authenticity/buzz around their most promoted artists.