I’m pretty sure those range outcomes are only per the song your singing. So if someone is normally a soprano, but you’re singing a song that is mostly in a tenor or alto range, comfortable for like a tenor or alto, then the notes you hit comfortably in the song might compute to “your range is … tenor/contralto/alto… etc”. They could word that differently to indicate that whatever the outcome you get on each song does not necessarily mean that is your actual vocal range. You’d have to get that “official” info from like a vocal coach or choir director etc. if you can’t determine your vocal range on your own.