We tend to imagine that the ecosystem that will bounce back is the current one, or something much like the current one.
Of course it's possible that the current ecosystem could be completely destabilized and die off, to be replaced by something radically different. It's happened many times in Earth's history.
I would generally consider the current ecosphere being replaced by something totally different as a variant of "The ecosphere recovering" as long as the successor has as much complexity as the predecessor - and exactly what the GP is talking about.
But of course there are far worse things than that sort of disaster. Earth turned into a snowball several times but geologic processes producing CO2 managed to fix the problem. The Sun is continuously getting brighter so that wouldn't be a problem nowadays. But eventually, in a billion years, the increasing brightness of the sun will cause the oceans to evaporate and complex life on Earth will probably never recover.
But of course there are far worse things than that sort of disaster. Earth turned into a snowball several times but geologic processes producing CO2 managed to fix the problem. The Sun is continuously getting brighter so that wouldn't be a problem nowadays. But eventually, in a billion years, the increasing brightness of the sun will cause the oceans to evaporate and complex life on Earth will probably never recover.