Regarding your last point, I think a knowledge worker smart enough to automate themselves out of a job will be smart enough to capitalize on that discovery. Moreover, there will always be tasks people will prefer done manually, knowledge-based or otherwise.
Standards are a good example. We love them, but, in a way, they eliminate the creation of middleware jobs that transform the data from one format to another.
As to your point about information, the volume of data these days requires increasingly sophisticated analysis. There seems to be a shift in sentiment around Big Data, that algorithms are still too unsophisticated to provide useful output, and that's a good sign that not only is there a lot of work to be done in this area, but a large volume of information doesn't automatically guarantee quality insight.
My point is that the qualitative difference between a creative and non-creative job is mitigated to some extent by all the 'non-creative' stuff we have to do every day. So even knowledge workers are not immune to 'dumb' automation. An example of this would be remote work and off-shoring, which has opened up software development projects to global competition.
However, the argument still stands - knowledge workers aren't unionized manual labour and if robots are going to replace everything, someone has to program the robots. And, there's easily going to be more 'robots' tomorrow than today for some time to come. So what could end the 'world automation' gravy train we are on right now?
IMHO, the average knowledge worker has a much clearer and more present danger that the chance they might be making themselves redundant - and one that would affect pretty much everyone, not just knowledge workers. They should more concerned about that other thing that destroys demand: financial destruction. The redundancy threat that knowledge workers should be concerned about are the sins of our owners coming home to roost; another depression.