Apple Mail has been able to detect appointments and reservations from email for years, just like Gmail -- and at least in my experience, Apple Mail pulls more useful information out of the mail when it creates the calendar entry. What they showed today is, in theory, something different. (I presume the difference is integrating it into the Siri assistant, not the mail application.)

The "AI" bit (a word they didn't mention during the keynote BTW) is the processing of a natural language user command to something the existing ML model can understand.

Most of the things shown during the keynote, can already be done with older iPhones - on device, but they need to be "talked to" like a computer, not with natural language that's not completely perfect.