Backchannel:

This story of Siri’s transformation, revealed for the first time here, might raise an eyebrow in much of the artificial intelligence world. Not that neural nets improved the system — of course they would do that — but that Apple was so quietly adept at doing it. Until recently, when Apple’s hiring in the AI field has stepped up and the company has made a few high-profile acquisitions, observers have viewed Apple as a laggard in what is shaping up as the most heated competition in the industry: the race to best use those powerful AI tools.

While other companies do their innovation in public, Apple has always been very good at making things behind the scenes and only releasing them when they are ready for the general public to use.