Funnily enough, I was having a conversation about this with a few people, just a couple of days ago.
Long story short, I've definitely seen a correlation between relevance and social media interaction. When I released music there was always a spike in interaction - as you'd expect. However, someone found that when they released music, there was no difference. I concluded that it must have been the way they promoted their social media when they released their music. You know - bloggers not including their twitter handle in the article, or something along those lines.
I always argue the case that big social media followings are the byproduct of an increase in your brand awareness. I also argue that social media should never be a priority. Things like a mailing list are a much better investment of your time and money compared to social media.
Anyway, your question is more directed towards platforms like Soundcloud... But with all of the things I have said considered, why bother trying to get comments/feedback? Most of the time, it won't be genuinely helpful as it's the usual "This is dope". You want constructive criticism, that's the key to improving.
Like others have said, engage/support others and you will receive the same in return. I'd definitely suggest you form some sort of group or collective where you help each other out, suggest improvements, etc. I know since forming my record label, just having artists around has led to everyone benefiting musically (and even outside of music).
Sorry for the Hell of a long answer to quite a simple question. But, I've definitely covered most aspects of the topic.
I hope I've helped!
Jordan
