Samsung is already preparing at least two new types of foldable smartphones to follow the Galaxy Fold. The new devices fold differently with one said to fold top to bottom, like a classic flip phone, while the other will fold outwards along the lines of the Huawei Mate X.
https://www.notebookcheck.net/Samsung-has-another-two-foldables-in-the-works.412925.0.html
Didn't realize this niche has room for another 2 devices from one manufacturer, but I certainly hope one gets the S-pen.