https://thenextweb.com/microsoft/2019/01/17/windows-10s-search-bar-and-cortana-split-up-on-good-terms/

Since Windows 10’s inception Cortana has been directly integrated into the search bar. The idea was that it would make it easier for people to find answers in one place, whether through text search or voice queries. But now it seems the company has decided the tools are better off on their own.

Microsoft has testing separating the tools for a few weeks, and is giving it a wider go-ahead with Insider Build 18317. After that, it should launch publicly with the next major update to Windows 10, which is currently scheduled for April.