File redirects behave as expected from redirects: they are an alternative name for a given file.
Redirects left after a file renaming
- breaks old references to the work when viewing older revisions in eg Wikipedia articles (before the passage of the Delinker) ;
- breaks external references (external websites, books, etc.) including attribution links ;
- breaks hotlinks ;
Overall, remember that redirects do not cost anything.
Redirects directly created
Redirects may be used to provide a permanent to a media expected to change − see Commons:Overwriting existing files#Using redirects
- meta:Don't delete redirects
- Wikipedia:Redirects are cheap