I see now that it does say on the artist's Twitter not to repost. I didn't see that before. That's kinda on me. I do think reposting images on places like 4chan should be an exception though, provided one isn't taking credit/removing signatures and such, given that this is an image board that cycles through and deletes old posts. In reality, this board is the only reason that I found out about Bludwing in the first place and became a patron.
Really though, my main issue is how 4chan handles DMCA takedown requests. They should just remove the image in question and move on without issuing warnings.