this is odd, Neversong doesn't exist in itch.io and i even check the official website to see where it might be. The game is exclusive to Steam only, so maybe someone stole the game and uploaded to itch.io thus leading to other possible scammers doing the same thing. This could be why it as remove.
Like I said, what happened with Neversong was clear. Someone else used a similar nickname and put the game in the list of those to be included. At this time there was an itch.io page available - so it was in fact to puchase on itch.io. But I wasn't wondering what happened with this game since the publisher himself explained the error. I was more wondering about the other games I mentioned and at least in teh case of Johann Weiss I was able to talk with the dev and he did not understand why it has been removed as well.