We will not have to wait for the release of Apple Watch Series 5 presentation as in the watchOS 6 GM version it is already present as the default software for Apple Watch Serie 4 and later.
Third-party apps must, therefore, be adapted to show their complications on this watch face, but luckily that is already the case with many apps. The dial will be available in watchOS 6, which will be available from September 19. Because of the full-screen format, you will only find the Meridian on the Apple Watch Series 4 and Series 5. That also means that on Series 3 and older will have the new Numbers watch face in watchOS 6.
Customization options include the ability to switch between the colors of the black and white dial, the color of the complications and the ability to customize the four complications on the watch face. The dial itself has an analog display that uses the hands and has no numbers.
The Nike+ version of the Apple Watch Series 5 also gets a number of new watch faces and you can find them on the Series 4 Nike+. There are three dials in total. With the colored analog face, the color adjusts to the position of the hands.
watchOS 6 final version will be available on September 19 for the Apple Watch Series 3 and newer. if you have a Series 2 or Series 1, then you have to wait a little longer. For those models, the update appears later in the fall, but the exact time is not yet known.