Very basic features like calling, texting, etc could go offline. But when I think of accuracy, I think most of the operations needs to be processed by its backend to give more accurate results and to check which results have failed Cortana, e.g. Cortana already tries to adjust the outcome when a user gives the same command second time, adjusting the query and giving new results to check if it has misinterpreted.
Yes, the issue is that Cortana needs to learn from its mistake. If Cortana is completely offline, there are chances that Microsoft will not know about the failure of Cortana on a particular command. And thus will decrease the chances of improvement.
I am thinking of these features in a grand vision. Let me know if I missed anything. :smile: