A typically reliable source has revealed new information about Samsung's next-generation foldable smartphones, the so-called Galaxy Z Fold 3 and Galaxy Z Flip 2. The pair's massive hardware upgrades remain unconfirmed, but it seems that Samsung will not announce either until the second half of 2021.
https://www.notebookcheck.net/A-leak-reveals-more-details-about-Samsung-s-next-Galaxy-Z-Fold-and-Galaxy-Z-Flip-smartphones.519858.0.html
Why are you presuming they'll offer 512GB models? The Z Fold 2 512GB model only available in select Asian markets).
They halved the storage from the 1st generation Fold (512GB in every market).
I'm constantly having to offload files from my Fold 2. Samsung hates offering high capacity models.