APPLE ACTIVELY DEVELOPING FOLDABLE CLAMSHELL IPHONE PROTOTYPES, FOLDING 8-INCH IPAD

Summary from the TLDR newsletter

Apple has been exploring foldable iPhones as early as 2018. It currently has at least two active clamshell prototypes. Apple is also developing a larger form-factor foldable iPad. The company recently discussed component orders with manufacturers in Asia. The project may still be canceled if the final product cannot meet Apple's design standards.