There are some new rumors (or analyst estimates, really) that Apple is working to adopt a microLED display in its next Watch Ultra smartwatch, to replace the currently-used OLED display. The new display, according to what we hear, will have a 2.1" display. Apple aims, it seems to release its first microLED display powered device in 2024, or even possibly 2023.
The current (Gen-1) Watch Ultra has an advanced 1.92" (49 mm) 2000 nits 502 x 410 pixels LTPO AMOLED display.
There has been rumors about Apple's first microLED wearable device for many years, and this latest rumor is not a big surprise, as Apple is indeed working hard to commercialize such displays.