I enjoy Quorum as well. But absolutely it's been reformulated, probably several times, it's a 40 year old cologne. Oak moss has been replaced, other ingredients have been sacrificed, it still smells pretty good but different to its original formulation. IFRA has handcuffed and made most classic frags to reformulate.
Is there any site that keeps a list of all fragrances that have been reformulated and probable ingredients that have been removed as well as what they were replaced by? For example, Halston Catalyst for men was a beautiful, complicated fragrance when I bought it in the 1990's. The current formuation since being sold to EA Fragrances, while still smelling great doesn't have nearly the complexity. I still have a little left of the original, and after doing an occasional comparison test, the original smells smoother and more intoxicating.
It's hard to completely place the blame on the new owners of classic fragrances, as certain ingredients that made the original formulas what they were are not allowed anymore.