With the July 2020 update, the Ninja/Stealth Mode was redesigned across the whole platform. Its functionality was moved to 2 different areas:
Depending on whether you were using it in collaboration or for recording, there are two ways of looking at the change.
I was using it in collaboration to move around the canvas freely
Once Always follow the host is set to OFF, Participants can simply select Zoom, move away, and confirm that they want to unfollow the Host to move around freely. This way, everyone can move around the same old way without having to switch between Stealth/Ninja.
Everyone can now also follow anyone they wish by choosing their name in the collaboration menu and selecting Follow. They now also know whether they're being followed and if they're moving someone else's screen, something that wasn't clear before.
I was using it during recording to move around the canvas without changing the camera
This functionality remains almost exactly the same, but gives you new possibilities. Now, instead of switching to Stealth/Ninja mode while recording, you can toggle the Camera Frame.
This way, the Camera Frame indicates the area that's getting recorded (as it used to be with Stealth Zoom) and can also now be moved independently, so you don't have to switch back and forth between Zoom modes to adjust it.