Maybe the superintelligence just convinces people to let it build things everywhere it wants to?
I don’t think the AI will work very hard initially on curing aging or on uploading. It might claim to “cure cancer” as a publicity stunt. I am not sure why AI 2027 seems to think that nanobots take so long to build. I expect crude nanotech to show up sooner in the tech tree. (“Nanobots” also aren’t really a specific technology, either. I expect there to be a lot of development there.)
I don’t predict a superintelligent singleton (having fused with the other AIs) would need to design a bioweapon or otherwise explicitly kill everyone. I expect it to simply transition into using more efficient tools than humans, and transfer the existing humans into hyperdomestication programs (“to humans what corgis are to wolves” is evocative and good, but probably doesn’t go far enough) or simply instruct humans to kill themselves and/or kill them with normal robots when necessary.
Yeah that all seems plausible as well. Idk.