Like its predecessor, the Galaxy Z Flip4 will likely be Samsung's best-selling foldable, but it appears Samsung will be loading up the more expensive Galaxy Z Fold4 with more upgrades. On the Flip side, changes are expected to be incremental—design-wise, at least.
https://www.notebookcheck.net/Samsung-Galaxy-Z-Flip4-to-be-more-of-the-same-as-leak-shatters-Galaxy-Z-Fold4-battery-hopes.615075.0.html