Microsoft has started to roll out a new version of the Windows 10 Intel Microcode KB4497165 update that is not optional, will automatically be installed, and your computer will be restarted. Microsoft has not updated the release notes for this update to include what has been changed. The update is reused by Microsoft to install new Intel microcodes as they become available for Windows 10 1903 and Windows 10 1909. The last noted update by Microsoft was from February 25, 2020, as shown below.
Source: https://www.bleepingcomputer.com/news/microsoft/new-windows-10-intel-microcodes-released-in-forced-kb4497165-update/