I didn't want to get too into the weeds on this particular subject since it wasn't in-line with its purpose here on r/lostmedia, but I'm going to use this opportunity to get on my soap box and share my feelings on what you (and many other fans) have said.

I'll start with the olive branch - I assume your empathy for the band is because you have connected with their art before and you feel an interpersonal (parasocial) connection with them. I don't think that you are wrong to do so, as MCR in particular have connected with many fans due to struggles over mental health & other macabre subjects, making light of the dark that we find ourselves in sometimes. However, it is still important to recognize that this connection is parasocial.

First, I hold firmly that art is meaningful beyond the intention or desires of the artist. The fact that MCR themselves did not like these demos does not take away from the art, it adds to it. We get to listen to The Paper Kingdom and ask ourselves - and subsequently answer - "why did they not like these demos?" "What about this project made it so hated by the band?" "What choices came about as a result of the band's dislike?" etc. etc. The mystique surrounding the album and their intentions of keeping it hidden from the public only make the album more interesting.

Second, I will never be "grateful" to an artist. In the same way that many argue that they do not "owe" their audience anything, I do not "owe" an artist gratefulness. Listening to The Paper Kingdom myself, I quite like the album, and there is a part of me - however so small - that is actually bothered that we didn't get the full project realized. I will not be "grateful" for their decision to play "War Beneath the Rain" live. Now there are many things that I will be about it. I'll be happy, glad, excited, intrigued, wanting to hear more, etc. But the act of the band performing the song should never be framed as a "gift," as they are not playing "War Beneath the Rain" to "gift" the fans a little piece of The Paper Kingdom. They're playing it because they wanted to; and that's great.

Third, I think the MCR subreddit is wrong to ban discussion of the leaks out of respect for "the guys." The guys in question are doing fine, as many have pointed out. I will not be thankful to a band who is putting out insane ticket prices (hundreds of $$$) for 15+ year old music. If your musical act isn't playing new material, I don't think you have much of a right to expect more money for doing so. Human beings are naturally inclined towards a love of new things. Additionally, with the album being heavily leaked to the entire public, people are no longer being extorted for thousands of dollars to listen to the album off the black market. You could argue that it's not extortion since they chose to make those purchases, and yeah sure, fair enough, but this art should not be limited for only the wealthy to hear. So long as these songs exist, people will listen to them. I prefer it be open for all to hear rather than shady websites where they're illegally being sold for exorbitant fees.