Instead of deleting, or still showing an older, and/or buggy version to be downloaded, why not add a middle option? Hide it.
- Allow users to be directed to download that latest version, or less-buggy version
- Allow submitter to be ready to fall back if the newer version is buggy or flawed
- Allow submitter to 'archive' their final work
- Good Game if submitter goes AWOL (or banned) for a very long time, you won't be able to download the previous version if the newest version is buggy.
- Decrease server storage capacity, if there are multiple version files to be kept (especially very large mod/files(s)