There's something you're missing here though, and that is that the minds in a superintelligent society will also be super-competent at convincing people to stop being luddites. They would probably capable of saying the PERFECT thing to convince virtually everyone, and for those that aren't convinced, they will eventually die off because they presumably will refuse life extension tech as well.

So, in the long term, we're talking about the whole planet here.

There's also the possibility that the superintelligent society does it by force as well. They may determine it's less immoral to force them to assimilate than it is to allow them to live regular human lives filled with suffering and hardship.