This add-on for Broadcast will try to relink a child post to the ex-parent post.

It works the same way as the find unlinked children bulk post action, but from within an unlinked child post:

• the parent post must have the same post type
• the same slug
• the same post status

After updating the unlinked child post, all blogs the user has access to will be searched for an equivalent post and if one is found, it is linked as the parent.