When you make a playlist private, it won't make any difference to how you see your playlists. On your Spotify profile, other people can't see private playlists that you make for your use only. It's not the same when you share a private playlist on social media or send it in a direct message. The people who get the message will see and play the playlist. Also, if your private playlist already has followers, they can still show it on their profiles.