It has happened. Many of us were expecting a hero launch or two happening at TI. It looks like Valve has already delivered on that front. After Game 1 of the EG vs Team Liquid elimination match.
A hero trailer for a New Dota 2 Hero: Snapfire was released.
From this short trailer, it looks like Snapfire is also a Keen much like Timbersaw and Sniper. It also seems like she's Timbersaw's aunt and rides a pet raptor much like Disruptor. She carries multiple guns and a flame thrower in her arsenal indicating that she might be a carry hero.
She has also been referenced in Mar's and the Axe Unleashed Immortal's responses
You should have offered me a cookie! – Mars (Enemy)
Axe doesn’t snack, Axe feasts! – Axe Unleashed (Enemy)
The Hero is scheduled to be released by Fall 2019.
We expect one more hero to be announced by Valve at this TI, keeping up the tradition of releasing two heroes every year.