I'll have to pay a small sum to do the same now, but that's not a big deal.
Spotify is the biggest music streaming platform, and having something I created, or played a part in creating, be on the platform, would be a personal accomplishment. It's just an item on my bucketlist, really. In a similar vein, I want to see somoene sing along to a song I write at a gig :)
Eventually the algorithm might even drop the songs in people's discovery queues, etc. But for fanbase interactions, I think local gigs + a Facebook page is the most important, to be honest. Then you tour and people should be able to discover you on their streaming platform of choice.
I haven't heard of 1000 True Fans, will look into what that is actually.
On the other hand I strongly suspect that the overwhelming majority of the music streamed by Spotify comes from "the industry" instead of artists uploading their own songs themselves. Implementing complicated filters (and playing the arms race game against people trying to work around them) is probably not worth it for them.
I know some people who are working on something like that with the added benefit* of being on Ethereum if that interests you... :)
I've been thinking about hash values for song sections, and then proving ownership by claiming a sequence of hashes. Could help ensure you aren't subconsciously ripping other music off, and make finding 'related' songs easy (covers, remixes, etc).
Spotify please hire me so I can work on this, tack.