After installing the update, when the user presses and holds on the mic button to record audio, another option appears on screen where they can swipe up to lock the recording. After doing that, the app will continue to record the voice note without you having to press and hold the mic button. You can still cancel the recording and delete the file without sending.
The update is out now on Android through the beta channel. No word yet on when it will reach Android stable and iOS.