I would postpone high-energy physics as well, but your argument seems mostly orthogonal to the claim you said you disagreed with.

New physics knowledge from the LHC could (with low probability, but much higher probability than a direct disaster) bring about powerful new technology: e.g. vastly more powerful computers that speed up AI development, or cheap energy sources that facilitate the creation of a global singleton. Given the past history of serendipitous scientific discovery and the Bostrom-Tegmark evidence against direct disaster, I think much more of the expected importance of the LHC comes from the former than from the latter.