[VMPhil]

In fairness, that was what happened in those heady days of renaming stuff to align brands internationally, I can remember similar happening with Opal Fruits/Starburst, Jif/Cif, that air freshener which changed its name etc... it would almost have been stranger if they didn't.

Well yes, but that was changing the name completely, McV was just an abbreviation of their full name. In the case of Marathon/Snickers, Opal Fruit/Starbust, Jif/Cif then yes you want the customer to know it's the same product with a new name.