I would not worry about reformulations unless money is not object. Do reformulations happen? Yes. Are they as bad as some make it? It depends on the scent. But you cant miss what you havent had. And if you try and like a different formulation it may mean you would like the older version less as you cut your teeth on the current one and that is the smell your mind will forever associate with that fragrance.
Another thing to consider is that what i remember a scent smelling like and what it actually smelt like may not be accurate. Our perceptions of scent at least for me constantly evolve. Scents i used to like i no longer care for. And fragrances i once despised are now my favorites. So if our perception of scents can change then maybe it is to some degree that we outgrow something and the scent is actually very close but our new impression of it is altered as we grew and evolved.
Now some may say "but i have a pre reformulation bottle and it smells nothing like the nee one. Fair enough but one thing that can and does happen many times is a scent will degrade over time. Slowly. Slow enough that changes may not register as they are so gradual. The bottle you buy today will not smell identical in ten years. There are so many factors at play. Especially if its a scent that has been around a decade or longer. And above all the hypotheticals reformulations are hear to stay no matter how many of us stomp our feet. I just dont see anyone taking the head of this beast so we either pay niche prices for vintage juice and stress out over even finding the stuff or you play the hand given to you and make the best of it. The only people i really feel for are the guys who wear a scent for years and it is them through and through and it gets discontinued.