The Galaxy Z Flip 5G is said to be succeeded by a device called the Z Flip3 in 2021. Its latest leak seems to confirm that it will still be a clamshell foldable smartphone, albeit one with a larger, potentially more useful secondary display. Its latest renders also show this putative feature alongside its main Dynamic AMOLED screen.
https://www.notebookcheck.net/Galaxy-Z-Flip3-new-high-quality-renders-integrate-the-next-gen-Samsung-clamshell-s-latest-leaks.537589.0.html