There is a difference between disagreeing with predictions about the future, and accusing the people making those predictions of lying about their own beliefs. This article does the latter.

And, ngl, it's been pretty wild watching the AI risk-skeptical narrative pivot from claiming that AI risk is a fringe issue which no experts think is plausible, to claiming that a large fraction of the relevant experts are lying about their beliefs.

No, they're not lying. The people who signed the letter did so because they believe what it says.