Well, depends on what "translation", and "optimization", means. If even shuffling a few things around counts as translation, then yes.. But then (near?) every change is translation, so it becomes meaningless as a notion. Better keep it more substantial, for changing some essential expressive ingredient of the code without changing functionality (and structure/architecture?) , much. Like language.

Sometimes translation may bring (speed) optimization, sometimes not (like python<->C) - some redundant loop in C will be faster than same loop in python, but removing it entirely would be even faster.. and no need for a translation just for that.

You probably think of "transformation" as general term, but that is much more primitive than "translation".