Although the Galaxy Fold has been officially delayed, it looks like two more such models are in the pipeline. For now, they are known as "Type G" and "Type S," but there is no official information regarding their commercial names or release date yet. However, at least one of them is rumored to be announced by the end of the year.
https://www.notebookcheck.net/Samsung-allegedly-working-on-two-more-foldables.418742.0.html
How could a 13" be a "handset"? Divided by 4 the screen would still be 7"!
If it's a full-screen device, it wouldn't get much larger than a 6-inch phablet, I guess. With a bit of struggle, it should be quite pocketable and almost easy to hold in one hand. What is designed to fold twice can be folded some more! :)