No, they aren’t rapidly aging, but they are now aging at a normal rate, and have been since Nordrassil was detonated. 30 years in the normal lifepsan of a Night Elf isn’t going to change them the same way it would a Human or Orc.
Or at least it shouldn’t.
Arguably the kaldorei should all be aging starting from the relative physical age they’ve held at for the past 10,000+ years (basically their peak physical prime) as it was preserved by the World Tree and the Well before it, but the novels and other written materials involving night elves seem to like really leaning into the idea that losing Nordrassil has them all aging fast and already experiencing the infirmities of advanced age, with the oldest ones implied to be dropping like flies and Tyrande noticing that her eyesight’s suffering as she wonders if she’s too old to still bear children.
Despite the logical timeline involved, the writers often seem to be in an all-fire hurry for the onset of mortality to be an immediate looming concern for the night elves, so the story materials overplay this idea that they’re already starting to physically break down from age when that really shouldn’t be an issue for several more centuries and in some cases even one or two millennia.
To be fairly, that mostly came from Wolfheart, a book Blizzard very actively goes out of its way to not acknowledged.
Higher intelligence is in fact not debatable. Zuldazar still exists because of the one time Queen Azshara actually showed a bit of mercy. The Kaldorei had decisively crushed every troll tribe in the world and the Zandalari were next and last. The trolls were simply overwhelmed by the magical abilities used against them. Turns out raw arcane magic is a lot more powerful than praying to a frog spirit.
You realize that Azshara and the Highborne were wielding the immense, cosmic power of the Well of Eternity in order to do that, yes? It wasn’t something the night elves were able to accomplish by virtue of intellect. It was raw, magical power from the most potent source on the planet that only they had access to.
Access to that is what gave them the intellect to be able to harness it. Look at the ogres in Draenor. They had access to some rocks left behind by Aggramar that gave off just enough arcane radiation to allow them to be able to cast a few spells but not enough to really enhance their intelligence a whole lot. So their use of it was clumsy and largely impractical. To this day, the Thalassian and Darnassian elves alike are still able to learn and wield arcane better than any others on the planet because of that initial access to the Well. They have titan levels of intelligence that are only limited by the mortal bodies theyre restricted to. Arcane and Fel magic aren’t like say holy magic. You cant just believe and make it happen. You have to practice, study, learn, and have discipline else itll blow up in your face(arcane), devour your soul(fel).
Arcane talent doesn’t directly translate into intelligence as a broad subject. We’ve seen elves make mistakes, make bad choices, misunderstand things, and be overcome tactically by other races.
Arcane translates to a sort of mathematics based intelligence perhaps, but intelligence is a much broader spectrum of skills and types of logical thinking than just that.
So when I say “elves are not more intelligent than humans/dwarves/trolls” that is what I mean. They aren’t a race of super geniuses. They have a great talent for a very specific type of magic, but there are other races that out-do them in other areas be it technology, strategy, or even empathy and social intelligence.
Even the smartest people can make bad judgment calls. Geniuses arent perfect. Intelligence gives an advantage but it takes much more than that to be a “god” or whatever. Elves are generally smarter than everyone else including most humans who are usually pretty stupid actually.