Forum itself needs to enable image uploading feature so that we will not depend on any third party before we can upload image and also that there will not be any issue like thus that we should fix anything.
Nice suggestion, but I don't think Theymos is going to listen to the request because this was asked when the imgur broken image issue came up. BTW, joker's talkimg is doing a fine job the forum.
Though from his explanation it seems very simple to fix broken images and one most not go one by follow to update their broken images due to his explanations. My concern is about those accounts that are ban, which already has some post with broken images is there a way to fix their broken images.
If you find the topic very interesting and you've the time, you can repost it with the broken links fixed and cite the user as the original author. Someone did that recently for a topic that the user is no more active on the forum, and it's a good way to keep those topics alive.