As this is the world of internet, a lot of stuff can be accessible forever, but some may dissapear anyway. File hosting providers often delete files that haven't been accessed or viewed after certain amount of time, even without notifying the author.
If a download link directs you to a broken page, you can report it through mail.
If a download link directs you back to this website, it means this repo was never available and it's not a dead link.
