Precisely.
the moral meme offers an evolutionary advantage for individuals that accept it.
Therefore you are defining "moral" as that which has an evolutionary advantage. Isn't "evolutionary advantage" that which better enables its possessor to reproduce and therefore survive (the fittest).
And haven't you then defined "moral" as survival - which you agree say "doesn't imply morally good?"
“Morally good” is a concept (meme) that provides survival advantage. Natural selection, or survival doesn’t contain value judgement. In other words “morally good” isn’t good or bad in an objective sense. It is just useful.