The usual way these partnerships worked is that Facebook allowed partners to ask users to grant them more account access than ordinary Facebook apps were allowe

The usual way these partnerships worked is that Facebook allowed partners to ask users to grant them more account access than ordinary Facebook apps were allowed - in the form of special partner-only Facebook app permissions that could only be obtained by approved apps. That is, it didn't bypass the normal need to request permission from the user, it just allowed them to request extra permissions. There's no reason to believe that the Spotify integration is any different. Even those leaked emails just talked about adding more permissions that companies could request.