A new predictive typing feature has been found hidden in the latest Windows 10 20H1 builds. This feature displays suggestions of words that Windows predicts you are going to write so that you can quickly select them. The feature was discovered by Albacore and from the GIF below, you can see text suggestions appear next to words as you type. It’s not clear if Microsoft will add inline text suggestions support to all third-party apps or it would only be supported in first-party applications.
Source: https://www.bleepingcomputer.com/news/microsoft/microsoft-is-bringing-predictive-typing-to-all-windows-10-apps/