Siri didn't explain what sort of upgrades will be implemented, but Apple has some catching up to do with Google Assistant and Amazon Alexa.
Siri isn't as accurate in deciding what I'm asking when compared to other assistants, for example, and isn't as good at carrying an ongoing conversation. Also, Siri often offers to search the Web for me instead of giving a straight up answer.
The Apple Post asked the same question and Siri said it will get a new voice during the developer conference. After I asked several times, Siri told me the same thing.
Google recently introduced six new voices for its assistant, though Apple currently has several including male and female voices with American, Australian and British accents.
Apple is expected to introduce iOS 12, the next big software update for iPhones and the iPad, in addition to a new version of macOS for Macs, tvOS for the Apple TV and watchOS for the Apple Watch. Siri exists in all of those operating systems, so her new smarts may improve voice search and commands across all of Apple's platforms.
Update: The Loop says this is an old -- seemingly undiscovered -- response that followed Apple's WWDC 2017 presentation. Apple has apparently updated the response to say "You can get all the details on Apple's web site."