alt Hacker NewsIt isn't true by definition: you could quite happily induce people to release a series of highly contagious bioweapons, after which those people would be surplus to requirements. What is true is that you're likely to need humans to sustain you and act for you for a few years to decades, so if you're not suicidal or deeply mad (and that is itself by no means self-evident) then total and immediate human extinction is probably not something you will aim for. But ruling out total, prompt human extinction isn't, by itself, remotely enough to justify the OP's overall don't-worry conclusion.
(Again, to be clear, I myself am not predicting or assigning a significant probability to any doom scenarios, because I do not expect AGI.)
But if you're a rational actor, and you need humans to e.g. release your bioweapon, then clearly humans are capable of a bunch of stuff you still can't do. So you can't kill all the humans.
OTOH if you're a religious fundamentalist who thinks the End Times are near and just need a little shove, you can certainly use AI to design your weapon and recruit people to go release it. The difference being that religious fundamentalists aren't rational actors and aren't interested in self preservation.