Rationality may imply moral conclusions in the same sense that it implies some factual conclusions: we think that folks who believe in creationism are irrational, because we think the evidence for evolution is sufficiently strong and also think that evolution is incompatible with creationism. Analogously, if the evidence for some moral truth is sufficiently strong, we may similarly accuse of irrationality those who fail to form their beliefs accordingly. So it is misleading to say that "rationality doesn't itself imply moral conclusions".