I can't imagine that either first or third person will ever vanish. First person and even present tense were common in the contemp YA of my childhood ('70s/'80s), but far from universal.
I've been writing mainly first lately, but third doesn't have to be distant from the MC. The trick is avoiding filtering: instead of "She wondered why he was never on time," you can just write, "Why was he never on time?" Bring us as close to the POV character's thoughts as possible.
Flaubert pioneered a technique called "free indirect discourse" and used it in Madame Bovary; tons of third-person YA and adult writers still use it today. Basically it means narrating in third person but in the character's voice, not that of an omniscient or neutral narrator: "Beth was going to be late, and then she would fail the test, and if she failed the test she would never go to college and would probably end up scrubbing toilets like her aunt Emmy who always smelled hideously of Clorox, and she would be better off dead." This is third person, but it's not distant at all; it's essentially Beth's voice. We are trapped in her head, just like with first person.
The cool thing about this third person technique is that you can have different perspectives in different chapters without the transition being as jarring as it might seem with several first person narrators. The narrative voice is basically a transparent lens; it's very flexible.
Now, you can also do a distant or omniscient narrator, but I think that's a hard sell in YA, and in contemporary fiction generally. You're more likely to see that in stories that have a self-consciously artificial aspect, like satirical fairy tale retellings. In a book like The Waking Dark, you have close POV chapters alternating with some broader omniscient chapters where the narrator generalizes about the town.
So, there is no one way to do third person. At its best, it can be way more flexible than first, though first always has the advantage of greater immediacy. I like them both; the story dictates which one I'll use.