Spoke once with a person working in Dji. She said they have bunch of people who have a job of flying the drones all day. Testing them and the firmware.
Its not that they just release something for us to check if its better. So i update right away.
I'm a validation engineer for a tech company and from experience I know bugs slip through. It's not possible for them to test every scenario.
now if warranty became an issue, I'd be happy to be a public beta tester, jump on the latest firmware and have them replace my bird if something went wrong