+1 for me as well.
Also, I’d like to see the same feature recently added for Asana/Siri (https://blog.asana.com/2017/11/new-siri-integration-asana-2/) added for Asana/Android/Google Assistant.
I had a solution for this for the past year using IFTTT that worked great and I used it all the time:
If You say "task to self $", then send an email from <myemail.address.com> to email@example.com
which would connect Google Assistant to Gmail, putting the “$” in the subject field and immediately create a new My Task for me; a great way to add a reminder or note on the fly by voice.
Unfortunately something at IFTTT broke a couple months ago and I since then only get an error “There was a problem with the Gmail service” which I reported to IFTTT and they acknowledged and promised to fix, but it’s been weeks.