CodePlex archives will be shut down after July 1st 2021.
We still have a bunch of links to it.
I'm sure there is a bunch of projects that were hosted there are now hosted somewhere else, like on GitHub. The project page will often advertise as such.
If you folks have the time and want to have your edit count incremented, feel free to dig into those posts and update the links to the new project page, if there is one.
If the project has not been migrated, then I suppose it's safe to say that the project will not be migrated and the link will rot on July 1st, so the link should be removed.
...and if the link is removed and the post makes no sense without it, then vote to delete it and/or flag as no longer needed and/or flag for moderator attention so we can remove the post.