This similar question has been asked before, but not fully answered. I cannot find any documentation. It appears that the tool does in-fact apply a transformation, but no way to tell which one. (Despite the fact that the Help for the tool implies that it does not). Others have stated that it also does not honor the a transformation defined in the Environments. Can we get some word or documentation from Esri on what is going on here? Transformations are not something that should be left up to assumptions.