Discord attachments are deleted (almost) immediately from the CDN when you delete the message that included them, so these links aren't very stable. I tried archiving them through Wayback Machine but you can't archive image links, so I uploaded them to Imgur as well.
Right, but when you delete an image from imgur you know the image is going away.
Years ago Discord wouldn't delete images uploaded as part of a post, they'd just get garbage-collected at some random future time. (And some would leak indefinitely) Thus, people got used to sharing these around and not caring about the original message.
Now it's near-instant as the message delete operation sends a Google Cloud delete API immediately. But people still share these around without knowing that. We don't know where those links originated so it's both a disclaimer and a mirror.
Thread mirror: (contained in the archived GitHub issue) https://i.imgur.com/mo8ZJkd.png
Last additional comment: (missing from the archive) https://i.imgur.com/Kq2IEfN.png