But if you’re asking if this tutorial teaches you how to create that AR face filter, the answer is no. This video series is about reproducing popular iOS controls - basically, the parts of the iOS user experience that makes it easy, engaging and helpful for the user to interact with your app. The AR face filter would be a completely different topic.
Just looking into it further, this can’t be right that the ChatViewController and DiscoverViewController are also being loaded into memory. This makes absolutely no sense IMO. For example a viewController in a TabBarViewController will be loaded when that tab first becomes active.