Apple has kicked the tires on next-generation microLED monitors for some years now. If you go with the company, it shouldn't come as a surprise. While they may not be the first to roll out new technologies and materials, they definitely work with them and plan for when the time will be right to release them into new products. When it comes to microLED, it looks like time may be next year.
According to the Economic Daily News, Apple is in advanced talks with Taiwanese display manufacturers to add microLED displays to Apple Watch by 2020. This sounds realistic, as Apple has been experimenting with this technique for a while. It is also consistent with a typical release damage, as Apple just redesigned the Watch 4 Series hardware last year. The 2019 series 5 will probably use the same design with upgraded internally and focus on software.
Although Apple is pushing out the same design this year, it doesn't necessarily preclude going with a newer screen, there are specific reasons why they want to use microLED. Firstly, it requires much less power, which improves battery life. This new screen will also allow for thinner and lighter designs, making it ideal for use in a redesigned Apple Watch.
So hopefully it works for microLED next year, as it would mean a thinner and lighter device with just as good or better battery life. Sounds good to me. We should have a pretty good idea between the end of this year and the beginning of next year, as the rumors in the supply chain will start to leak as prototypes get rounds and testing and production begin.