Microsoft has released a preview version. The most significant new feature is called the quake mode, and it is not clear why it is called that way. Quake mode allows you to use keyboard shortcuts to open the terminal from anywhere. With this, you can now also set it as the default terminal.
This means that all command-line applications are launched in the Windows terminal, and they should also be run from the context menu. This is a key new feature of Windows Terminal 1.9. This is not a major update or anything. Presumably, whenever Windows Terminal 2.0 arrives, there will be a lot of new features.
Another feature Microsoft touted is the new settings UI in the Windows terminal, which has been included in open source applications. Previously, you had to edit the JSON file to change the settings. In addition to Windows Terminal 1.9, Microsoft also introduced some new features.
In the Windows subsystem for Linux, GUI applications and GPU acceleration are now supported. However, Windows Insiders has been previewing for some time.