First, the trash setup doesn't use a rootshare, a term which is used to describe a single share that shows all the normal Unraid shares as folders. Trash recommends only using a single normal Unraid share for your media all the way through the import process, from acquisition to long term storage. That means having your downloads in the same share as your organized media.
Unraid shares are simply identically named root folders on each disk, so to move the contents of /mnt/user/tv to /mnt/user/media/tv the most efficient way to do that is directly on each disk one at a time move /mnt/disk1/tv to /mnt/disk1/media/tv. That move would be almost instant, and you would just repeat this action on each disk that contained the root folder /mnt/diskX/tv. Using mc at the Unraid console would be the most efficient way. Just be sure never to mix /mnt/user paths with other paths. For the purposes of this example, stay out of /mnt/user entirely.
The trash guides really only have value for someone wishing to utilize torrents to keep copies of what they acquire available for long term seeding, and they force you to give up any security and storage granularity for all those files. I wouldn't bother going through all the hassle just on a whim.