Now that siri shortcuts is out, I can enter spotify URIs and record a message for Siri to run it.
All that is missing is Spotify's support for URI that opens my saved "Songs" list and auto plays
Instructions for using Siri Shortcuts: 0) download Apple's free "Shortcuts" app from the appstore
1) create and edit a new shortcut
2) add a "URL" with a spotify URI as the content (ex: "spotify:user:XXXXX:playlists") 3) add an "Open URLs" object (causes url to open in safari, first time you run you have to confirm a dialog, but subsequent calls dont need to do this) 4) set a Siri Phrase to map a siri voice command to run this shortcut note: if you run this from the lock screen, this will require you to unlock the device to complete