This update moved Cortana from an all-or-nothing permissions model, where you have to grant a whole bunch of permissions before you can use any Cortana features

This update moved Cortana from an all-or-nothing permissions model, where you have to grant a whole bunch of permissions before you can use any Cortana features at all, to a more granular model where the permissions are broken up into a handful of categories and you only have to enable the ones required for the specific features you want to use. These permissions are off by default as well (this includes microphone access and listening for "hey Cortana"), but you'll be asked to grant the relevant permissions when you try to use a feature that requires them. However, it's also true that there's no longer a supported way to turn off web searches in the search box (at least as far as I know).