As you've been reading, most brands have reformulated their classics, whether because current tastes are for lighter stuff, or because IFRA has banned many ingredients. Probably, very few classics are exactly as they were. That said, I'd say that there are still many perfumes that, despite some differences, are still great (female perfumery has been hit harder than male, I would argue). I'm sure one could argue forever about each one, but in the areas you cite, off the top of my head:
Caron Yatagan: arresting vegetal top, deep woods drydown. Perhaps it has less animalics than before, but none the worse for it.
Aramis: musky leather, still great (as is the perhaps even better companion, Estee Lauder Azuree, a brighter version of Aramis).
$$$ Guerlain Derby: still excellent citrus-leather-wood.
Chanel Egoiste (the regular Egoiste, not platinum): here I must say I have not smelled the latest batch, which according to some is weaker. What I see here in the US is still good. Incidentally, I had not heard of changes to Platinum Egoiste, but I haven't followed.
Chanel Antaeus: superspicy. This could be a bit controversial. Again, less animalics than before. But still packs a punch with its intense and slightly objectionable spicy profile.
Kouros: according to many, the very latest batch has lost all the dirt. But in many stores there are still older batches (the bottle has a metal base, and the batch code ends in -02), which are worth stocking up, if found.
Then of course there's expensive niche perfumery, which has plenty of fantastic stuff, but that's another story.