If the dependency graph is evaluated, then you don't need this. If it is not evaluated yet (i.e. on redo) this is not enough.

It should be enough to replace CTX_data_depsgraph with CTX_data_evaluated_depsgraph few lines above and remove this manual copy.

It is unreliable to use BKE_object_where_is_calc on original object: it might depend on constraints which needs final geometry which does not exist in an original domain.

Not sure why this is even needed. Is it for applying transform when both children and parent are selected?
In any case, seems you should do BKE_object_transform_copy(ob, ob_eval); here.