Yep, whenever we post a new version, the plugin disappears from the general lists until the file passes LoTRO Interface's virus/malware tests.
If you add the plugin to your Favorites, you will be able to see that it has an "Update Pending" status. If you click on a favorite with the Update Pending status, you will get the plugins page and be able to read any description changes as well as download old versions but you can't get the new version until it is approved.
Additionally, the number of people with a plugin in their Favorites is another fairly good gauge of how popular the plugin really is. Many people forget to rate a plugin, but if they have it on their Favorites list it means they liked it enough to look for updates.