Instead of Siri Integration in the way this post is requesting, Siri Shortcuts Support would be far more useful and beneficial to the users, and easier for Spotify to implement. Please vote for this idea instead:
Now that Apple has announced an API for developers to have access to Siri, it would great if Spotify supported it, as well as announcing Siri support in the update release notes instead of the worthless "We're always making changes and improvements to Spotify" messages, that make finding new features a guessing game. (Like support for 3D Touch.)
Updated on 2019-10-07
Spotify is now integrated into Siri on Apple iOS devices.
This eagerly awaited feature will let you control Spotify and play music, podcasts, and playlists using the power of your voice. Now you can listen to Disney Hits or an exclusive podcast like Set It Straight with Midland at work, home, on the commute, while exercising, or doing chores, all by saying the familiar “Hey Siri, play. . . ” to hear the audio you want. Just make sure to update your iPhone to iOS 13 – from there, remember to end each phrase with “on Spotify.”
The Siri integration is also available on our new and improved app for iPad.