They aren't claiming to have taught Siri to add events... They're claiming to have integrated with RTM.
I suspect there might be an issue with having a calendar AND a task list both, though... Like, you can't.
From the article: "we had to teach Siri to add tasks to Remember The Milk [...] and we're super excited to announce that we've done just that!"
If you leave out that bit, then you're correct, they were claiming they taught Siri to add events. But that bit is important.
They aren't claiming to have taught Siri to add events... They're claiming to have integrated with RTM.
I suspect there might be an issue with having a calendar AND a task list both, though... Like, you can't.