Duplicate, scale -1 in X, unparent, freeze again

SymmetrizeModel.py

import maya.cmds as cmds
import pymel.core as pm
import pymel.core.datatypes as dt

sel = pm.ls(selection=True)
shapeNode = pm.listRelatives(sel[0])[0]

pm.constructionHistory(shapeNode)
pm.makeIdentity(sel[0], apply=True, t=True, r=True, s=True)

# Create new group
origGrp = pm.group(empty=True, n='original_Group')

# Set the new group to be the selected object's parent
sel[0].setParent(origGrp)

# Duplicate the group
dupGrp = pm.duplicate(origGrp)[0]  # Get the first duplicated object (even if only 1 exists)

# Set Scale
dupGrp.setScale(dt.Vector(-1, 1, 1))

# Get duplicated object
dupObj = dupGrp.listRelatives(children=True)[0]

dupObj.setParent(None)
pm.delete(dupGrp)

dupShapeNode = pm.listRelatives(dupObj)[0]

pm.constructionHistory(dupShapeNode)
pm.makeIdentity(dupObj, apply=True, t=True, r=True, s=True)