Albeit, most users miss some functions and services that are only available in defunct Google Now (such as package tracking), there isn't any denying that Google assistant has got substantial advantages over the older Google Now voice interface.
While, there isn't any apparent new feature, but clues hidden inside the apk reveals possible changes coming down the pipe in the future.
The APK Teardown contains a reference to a “keyboard_toggle” and a “type_container,” presumably bringing text inputs in addition to voice-commands, more akin to how Assistant works in the chat app, Allo.
However, the mystery item of this update remains Search gestures: which going by the name and descriptions in the text, may mean performing search with a swipe down on the home screen, whereby users will be able to choose a default type of search, including options for In Apps.
And the Search gestures could be as simple as a swipe to open the search bar without reaching up to tap on the app, but since this feature is directly tied to a gesture on the home screen, it will only operate within the Google Now Launcher.