@PedeJo it would have to clear that humanity will never drop below 1 billion. It's probably not possible for that to be the case. Especially given eventual heat death of the universe.
@Daniel_MC Shouldn't the "never" option include reliable indication that we will survive the death of the sun/earth, but specifically not deal with longer time horizons? Or else its a pointless question.
@DavidHiggs Once it’s time to resolve in 2100, no matter how long a future timeframe there will always be a non-zero probability of it happening, say within the following million years; or 100 years (2200) or even the following year (2101). It is not an impossibility, nor a contradiction in principle with zero probability. So it cannot ever resolve to “never”.
There is no need to presupose much more “certain” causes like the heat-death or cold-death of the universe. Even the most unlikely yet conceivable cause, if it is not a logical contradiction, is enough to resolve it to “after 2100” at that point.