I can confirm watch os 2 does do this and os 2 is solid.
I can confirm this as well and what is so nice is that you do not need to wait or keep you arm up for anything you ask siri to do. Haptic feedback will inform you if it needs more info or will give you feedback that it added a reminder or appt, etc.
I love just saying "Hey Siri - send a text to my wife and tell her I will be home in 15 minutes" and immediately lower my arm knowing that SIRI is going to send it and almost always perfect with the wording. Actually way more accurate than me typing with my big fingers and that stupid auto correct ;o)
I know I can send a text with less words, but I like the natural flow and siri doesn't add the extra words. Very slick...
I've mentioned some commands before but I love reminding about some I use and how I use it...
"Hey Siri - Add Apple and Bananas to my grocery lists" - I raise my wrist and say Hey Siri and as soon as the screen looks to be responding, I say my command and lower my arm. No waiting, no wondering. A few seconds later, I get a haptic feedback confirming the addition to my grocery list on my phone under reminders.
The cool feature is that even if your phone is not connected to your watch or you left it at home, you can still add the reminder to the watch (same for appt's, etc) and they will still work. Also, when your phone comes back in range, the watch will update the phone. Very slick... same for IM Messages when you are on a known wi-fi network your phone isn't with you or out of range. You can have siri send IM Messages and it will be delivered and will eventually, when the phone is back in range, it will update your phones message history.