You might be sharing more data than you care to offer when you pre-save an album on Spotify. Billboard has pointed out that labels sometimes ask for permission to track an extensive amount of info about your account and listening habits, including your email address, your recent play history and who you follow. They'll also ask for the abilities to manage who you follow, add and remove library items and create playlists. As you might imagine, a lot of that isn't necessary to find out if you want to listen to a new album.
This is legal, but there are concerns that Spotify is not only tolerating excessive data collection with pre-saves, but isn't completely transparent. The permission request section requires that you tap a "learn more" link to see exactly what a label wants, and there's a good chance listeners will simply skip that so they can listen to the latest Drake single. A rival like Apple Music is clearer on permissions, doesn't share personally identifying info and doesn't offer account control beyond creating playlists (again with permission).
Spotify declined to comment.
Labels aren't necessarily going to abuse this data to pepper you with ads or construct profiles. You don't know for sure that they'll be respectful, though, and that's assuming you know what they're gathering in the first place. If there's any consolation, it's that the increasing attention to privacy may push Spotify and labels into collecting only the data they actually need to track demand.