“Precludes” means “to make impossible by necessary consequence : rule out in advance”. That is, that determinism is not compatible with free will.
And, what is “free will”, again? I don’t believe in the usual version of it. Compatiblist free will is nice and all but I don’t consider it real free will.
If we truly live in a determanistic universe then we have already had this conversation. We will always have this conversation.
It will always be the same conversation.
You apparently have a different version of “deterministic” than I do. What’s yours?
If there is no free will then knowing those facts is just part of the motions that we go through. There is no free will available in your situation to chose a path of morality or not, it’s just going to run ‘as programed’.
So in your scenario it is unrelated, and indeterminable if what we consider morality will break down.