Is it actually self-stabilizing though? Or I guess it depends what you mean by that. AFAIK the earth has been in many different stages lasting for long times, changing from one to the other due to various factors. But it's unlikely earth will return to a pre-industrial state, even after millions of years, especially if we keep emitting CO2, I believe.

But if you just mean that a new plateau will be reached eventually, then sure, a mass extinction will still happen though.