There is no official word on that.
You should probably define “supported” though.
The part of Ionic that generates native apps is handled by Cordova and is the exact same one as for Ionic 2+ - so this won’t break.
The only thing that could go away is support for a) external services like Ionic Pro or b) some browser changes in future iOS or Android versions that break Ionic v1 code. Both is highly unlikely because a) there are still loads of Ionic v1 out there (and in enterprise environments) and b) because HTML doesn’t tend to break backwards compatibility.