I somewhat disagree with the first one. Melanie has performed a bunch of unreleased songs before, and it's difficult to find a line between what's "okay and not okay to listen to".
Two examples:
Is it okay to listen to songs like "Dear Porcupines" and "Night Mime", since Melanie has performed them? She obviously doesn't mind those songs being heard, but she's not profiting from your stream. If yes, is it only okay to listen to the live versions, or are the leaked demos fair game as well?
Melanie has previously released songs like "I Think I'm Crazy", and "PIGGYBACK" exclusively on SoundCloud. The former has been removed from the platform. Would it be okay to listen to "I Think I'm Crazy"? Even though she removed it, it was still released. If the argument is "Don't listen because Melanie doesn't profit from it", then we shouldn't stream those songs.
The point here is, you should just listen to what you want to, as it will change nothing whether you do or not.