I think spotify is responsible for creating playlists you see in the app. In each country there is a spotify team which is responsible for updating these playlists. For example new music Friday will change per country. Swiss French hip hop is the responsibility of the swiss spotify team.
I can imagine a lot of people want certain songs in the list, like the artist or the label. I don't think you can influence this as a user. But of course you can create a playlist and promote this in all kind of ways, like spotify playlist exchange or Facebook.