FYI, my understanding is that all the asteroids capable of posing an existential threat to humanity are known and tracked. Smaller asteroids like this one are not, but there is an upper bound on the possible damage they can do, and the damage is pretty small in expectation (i.e., when weighted by the chance of a collision).

On the other hand, it's still possible that a long-period comet or rogue planet could come out of nowhere and wipe humanity out. Presumably the odds are extremely remote, judging by the rarity of extinction-level events in the geological record.