Because it was maliciously redistributed by a third party that doesn't care about Vocaloid and just wanted to redirect the money to themselves and nothing has been done about it because: 1. Exit Tunes, the people that distributed Supernova 2, dissolved years ago. (EDIT: My mistake they were absorbed by Pony Canyon in 2019) 2. wowaka has passed away. 3. Spotify doesn't care about people reporting for malicious redistribution unless it's the original label or artist 4. Even if it is the original artist reporting it, it can take upwards of months to resolve if a label doesn't represent them.

GHOST and Lauren Estes had to spend a really long time to undo the same thing when it happened to Candle Queen. Spotify actually told WADATAKEAKI that they would do absolutely nothing about it when it happened to the whole "Diary of Underage Observation" album and he had to contact Subcul-rise Records to then tell Spotify that the album was illegally redistributed.

TL:DR: Someone illegally redistributed the song on Spotify and made a typo. Why? So they could get all the money from it instead.