Intelligence alone does not have ethical implications w.r.t. how we treat the intelligent entity. Suffering has ethical implications, but intelligence does not imply suffering. There's no evidence that LLMs can suffer (note that that's less evidence than for, say, crayfish suffering).
While I agree that suffering has ethical connotations, I don't think it makes sense to treat it as a requirement. A Buddhist who manages to achieve enlightenment and overcome suffering does not immediately cease to be a moral patient, right?
