Really, Siri is an agent. Agents thrive when the subjacent model capabilities are higher, as it unlocks a series of other use cases that are hard to accomplish when the basic Natural Language Processing layer is weak.

The better the basic NLP tasks like named entity recognition, PoS tagging, Dependency Parsing, Semantic Role Labelling, Event Extraction, Constituency parsing, Classification/Categorization, Question Answering, etc, are implemented by the model layer, the farther you can go on implementing meaningful use-cases in your agent.

Apple can now concentrate on making Siri a really useful and powerful agent.