@AriesWarlock. I have no clue. At the beginning of July, the author closed their Twitter/X account and started deleting all of their works from Pixiv. I checked their DLsite and decided to purchase the other Hololive book that was still available (i.e., this one). A few days ago, I got a notification that all their other books had been deleted or taken down. I was fortunate enough to save this one; such a shame about all the others.
If I had to take a guess, judging by how the art in this book feels off putting, I'm gonna assume that the artist was accused of using A.I in their work.