Great summaries/comments!
I think this is an original argument of Tomasik’s.
The specific calculations are probably original, but the basic idea that being in a simulation would probably reduce the importance of long-term outcomes was discussed by others, such as the people mentioned in this section.
Thanks for the question. :)
That sounds like a definition of physicalism in general rather than eliminativism specifically?
I agree with the analogies in Tim’s comment. As he says, the idea is that eliminativism says all physical processes are kind of on the same footing as far as not containing (the philosophically laden version of) consciousness. So it’s more plausible we’d treat all physical processes as in the same boat rather than drawing sharp dividing lines.