According to reports from Korea, Apple is designing a new foldable MacBook laptop, that will adopt a large 20.25 foldable OLED display. Apple is collaborating with Samsung or LG Display on this project, the report does not detail that.
The reports also suggest that Apple is looking into smaller foldable display - including a foldable iPhone and a foldable iPad Mini (10-inch when open) - but these projects aren't confirmed yet.
There are already some foldable OLED laptops on the market, for example the Asus ZenBook 17 Fold OLED with a 17.3" 2560x1920 made by BOE, and Lenovo's ThinkPad X1 Fold 16.3 2022 ( 16.3" 2024x2560 touch-enable foldable OLED).
It is very much likely that Apple is at least testing the latest foldable OLED designs for future devices. Apple has completed the switch to OLED displays across its entire iPhone range, and is also using OLED displays in its weareable devices. The next stage for Apple is to start adopting OLED displays in its tablet devices. Following that, it makes sense for Apple to look at new foldable form factors.