I like Kent Nelson as much as the next guy, but I'd argue that the Golden Age boom characters have been mishandled since the 60s. I also like the Earth-2 concept as much as the next guy and the fact that Broome & Infantino & Co. weren't willing to let the originals fade into obscurity. But seriously ... they all deserved to be mainstream contemporaries, not Alt-Heroes. Which is why Late-Silver and Bronze Age DC are essentially just one big never-ending Earth-1 and Earth-2 crossover and why COIE was imperative, even if having to deal with all the real-time aging ridiculousness of Earth-2 and duplicate characters led to a lot of narrative snafus.
Anyway, getting on point - the whole DCU was flashpointed to crap. The way I'm figuring it in my own headspace, Khalid IS the New 52 Kent Nelson. I don't suppose I need "every" JSA guy to show up as a veteran the same age and well into their career like Batman (a guy can dream, though), but I also don't need them all to be like, 1940 manly man burly barrel chested cliches. Or else we're just going to have yet another massive cadre of white guys with the same exact heavyweight muscles and body types, representing nobody. (I mean I'm 'Caucasian', blue-eyed, 29, semi-talented, lifting weights constantly, and better than average looking and even I can't find all that much representation in a legion of would-be square-jawed, macho Bruce Wayne clones with "slightly" different personalities and day jobs.)
But ... skinny college guy from Brooklyn with working class parents? Khalid is essentially any given person on my friends list.