All points could be answered with “probably yes”.
If you see what Deep Learning methods are able to do today (and especially when they fail), you could imagine to create these applications in a less amount of time and will less resources.
So e.g. for your last example: if you train a model, which would achieve a high accuracy of person identification with a single sound sample of 1 second, then yes, Siri would then be able to classify you instantly.