Love it but it only makes sense as a Spotify digital release.
Nothing should ever be released as a streaming-only release.
I get why physical releases may not be possible in all cases, but any project should at least be released for purchase as a download.
With Spotify, contracts expire and things can be pulled from the service (just like Netflix, etc.).
With a download release, you can download it and keep it for as long as you can store the data.
With a streaming-only release, they can rest assured even *more* fans will simply download the audio for free off of YouTube than already are.