Note that they're not claiming that their LLM is 1-bit - they're saying that there is a 1-bit era of LLMs. What they do say is that their approach is a variant

Note that they're not claiming that their LLM is 1-bit - they're saying that there is a 1-bit era of LLMs. What they do say is that their approach is a variant of a 1-bit LLM variant, namely a ternary LLM (they explicitly state that in the abstract).