Cortana improvements will be coming later in 2020 & due to radical changes, existing support going away in Windows 10 versions at ‘end-of-support’ dates.  This change is designed to reduce maintenance & encourage users to keep up-to-date with supported versions of WIN10

https://www.windowscentral.com/cortana-support-going-away-windows-10-versions-end-support-dates

Microsoft detailed several changes and improvements coming soon to Cortana with a focus on productivity. As part of the moves, however, the company revealed that it will drop Cortana support from older versions of Windows 10. Specifically, versions that have reached their end-of-support dates will lose Cortana.