When is

DirecTV has had no recycle bin like your home computer. DIRECTV STREAM / DirecTV via Internet are the same.

The answer to "when" may be never. Not impossible it could change one day, but at the moment there is no information that it will.

So it is wait until it might happen or if extremely important to go with a service that already has that implemented.

DirecTV Stream does, indeed, have an "Undelete" feature. You just have to do right away if you accidentally delete a recording. 

What streaming device are you using?

The trash can icon they currently have is completely useless, at to me.  You'd have to realize right then and there you deleted something by accident before moving up or down.

Xfinity (which I thoroughly detest) had the best feature.  At the bottom of the Recordings List there was a folder titled DELETED or RECENTLY DELETED.  And it kept a list of all recordings deleted for "x" number of days or a week that could be restored.  Now THAT was great!!!

With DTV Stream I've accidently deleted recordings and FOLDERS of recordings by accident with no way to ever view them or restore them.

I would LOVE to see DIRECTV STREAM add something like that.  It would put them ahead of other services.  (In my opinion they are already ahead of others), but this would make it even better because I watch very little live TV.  Only tons of recordings.

Tivo has that "undelete" feature, too.  I doubt it's a priority for DirecTV.  The Satellite service never had it.  At least Stream gives you a quick "oops" feature to undelete. But you have to catch it right away.