"I love Apple, and I consider it the privilege of a lifetime to have worked here for almost 14 years, and I'm very excited about this new role." That's how Tim Cook opened the iPhone 4S event in October 2011, his first product launch as Apple's CEO.

Fifteen years later, we're on the precipice of another landmark Apple event for the chief of one of the world's most iconic and valuable companies. This Worldwide Developers Conference will be Cook's last before he hands over the reins to incoming CEO John Ternus in September, likely just ahead of that month's iPhone event. 

There's not really a leadership change playbook at the company, as Cook took over from Steve Jobs as his struggle with pancreatic cancer took a turn for the worse. That makes this moment uncharted territory.

WWDC, Apple's annual software developer conference, has hosted many exciting product launches across the years, from the first iOS to Apple Silicon to Apple Intelligence. It's a moment of hellos, rather than goodbyes -- but this one will be different. As Cook takes the stage, he'll close out a hugely successful era in Apple's history -- one that saw it become a trillion-dollar company, several times over.

"WWDC 2026 carries far more significance than a normal developer conference," said Paolo Pescatore, an analyst at PP Foresight. "As this is Tim Cook's final WWDC as Apple CEO, it is as much a symbolic handover moment as a software showcase."

It's unclear whether Ternus will take the stage at WWDC or delay his public debut as CEO until the rumored iPhone event in September. Ternus has a background in hardware rather than software, so WWDC isn't his natural environment, although he did introduce Apple Silicon at the virtual event during the COVID-19 pandemic. That doesn't mean he won't make an appearance on stage with Cook for a public passing of the baton.

Ternus arrives at an important time for the company, said Ben Wood, chief analyst at CCS Insight. "If rumors are to be believed, there are a slew of new products to be announced over the next 12 months, which will give him a chance to start his tenure with a bang."

As for what references Cook will make to his departure, he may well downplay its significance rather than want to drag out his final bow. "My expectation is that he will want as little fuss as possible, but will focus on some of the major milestones Apple has achieved under his stewardship," Wood said.

He's also unlikely to want to pull focus too much from WWDC's announcements, which will include updates to Apple's operating systems, including iOS, MacOS, WatchOS and iPadOS, but will also include an expected revamp of Siri.

Getting Siri across the finish line

In many ways, Siri is the overarching theme of Cook's leadership.

Apple launched the voice assistant in October 2011, just months into Cook's tenure as CEO. Its arrival provoked skepticism, and the technology fell short of people's sci-fi-informed ideas of an intuitive digital personal assistant. Despite initial hype, Siri just didn't work that well. That was three years before Amazon debuted Alexa, and Apple never really caught up.

In part, this was because Apple prioritized privacy and security for Siri, which limited the assistant's features compared with Alexa. But what was also lacking in Siri then, and has been ever since, are the kind of reasoning and language skills that only advancements in artificial intelligence and the development of large language models a decade later could provide.

It seemed, therefore, when Apple announced Apple Intelligence and its integration with Siri at WWDC 2024, that the voice assistant was about to finally fulfill its original promise. But almost two years later, following delay after delay, the revamped Siri still hasn't seen the light of day. Last month, Apple agreed to pay $250 million to settle several legal complaints alleging that it misled people about the iPhone's capabilities.

All signs point to this WWDC as the moment for the Siri we've been waiting for all these years. If anything, Cook's retirement almost confirms it. 

Siri is his baby (even if it was Jobs who originally acquired the technology), and Cook doesn't seem like the type to abandon a project in the final moments before its completion. It would be wholly surprising if he didn't see it through. It will be an integral part of many of the upcoming products the company is rumored to have in the pipeline, such as AirPods with cameras or a robotic iPad for your home.

Instead, it feels more likely that he will send advanced Siri out into the world to live its best life as a fully realized AI assistant and then retire in peace to live his best outdoorsy life, full of books and very little phone time.

It'll be intriguing to see how the closing of this chapter will play out on stage. CNET staffers will be in person at the event live from Apple Park, so make sure to follow all of our WWDC coverage on Monday.