The move means that users no longer have to install the updates manually, e.g. by selecting the "check for updates" button in the Windows Update settings, or by installing the upgrade using the Windows Update Assistant.
You can still stop the updates to a new version of Windows 10 using update blocks. Such update blocks prevent the installation on devices with potential or known issues. However this means that Windows will automatically update by default unless a block is triggered.
New updates are released under the "targeted deployment" status initially which limits the availability to devices that are the most likely to be fully compatible with the new release of Windows.