Cook said in an email to his team members on Tuesday, "Our technology must be infused with the values we all hold dear".
This lack of data might have hampered the company's work as machine learning algorithms require massive amounts of "training data" in order to be able to function well - but Mr Giannandrea's hire is unlikely to change this approach.
Giannandrea has been a stalwart proponent of the benefits of artificial intelligence in his limited interviews with the media. He came originally from Metaweb when Google acquired the company in 2010. Metaweb - at that time - was focusing its efforts on building something described as a "database of the world's knowledge".
He departs a company that's widely considered to be among the leaders in AI research for one that's perceived to have struggled to get to grips with the same technology. John Giannandrea is now officially part of Apple's team and his main objective is to help Apple improve Siri.
The company will also allow users to completely delete their Apple IDs, which was earlier possible only by contacting the company. Apple's smart speaker - the Homepod - has received mixed reviews since its launch a year ago, so Giannandrea's expertise is a major coup for the company.
"What I object to is this assumption that we will leap to some kind of super-intelligent system that will then make humans obsolete", he said.
In March, technology site The Information detailed seven years of infighting within the Siri team at Apple, with multiple attempts to reorganise the basic technology that underpins the feature falling prey to internal politics which limited attempts to improve the overall product. At the time, John pointed towards Google Home as a hint of what's coming. Facebook, Google, Amazon and Microsoft employ huge numbers of researchers working across a number of areas, who are also heavily involved in the wider global AI community.
It seems Apple thinks it has something to learn from Google. In fact, Google directly banned its employees from publishing any of their AI research.
Apple has a very strict policy when it comes to the handling of personal data of its users.
Lately, leading Silicon Valley companies have seen major shake-ups at higher level management, in the AI space. It is unlikely that Google's AI department will suffer as much as we expect Apple's to progress.