The culling of Windows features you’ve never heard of but that will affect hundreds of thousands of people because Windows is just that popular so even an unknown feature is used by gobs of people continues.
The legacy console mode is deprecated and no longer being updated. In future Windows releases, it will be available as an optional Feature on Demand. This feature won’t be installed by default.
Microsoft’s “Deprecated features for Windows client” page
Basically, with legacy console mode you could revert to an older version of the Windows console in case some program wasn’t working correctly in the latest version installed with your copy of Windows.
