Countdown featured an Earth on which the next generation of heroes took over for the old guard...which was then blown up and completely destroyed by Superboy/man-Prime because he found the idea of a world in which the next generation took over for the A-list heroes to be that offensive.
Multiversity: The Just featured an Earth in which the old guard had retired and featured pretty much every character that either first appeared or rose to some level of prominence during the post-Crisis '90s, from the big names like Nightwing (Dick), Flash (Wally), Green Lantern (Kyle), and Superboy (Kon-El), to B-listers like Dr. Mid-Nite (Pieter Cross), all the way down to Z-listers like various New Bloods, members of the Conglomerate, and Alpha Centurion and nearly every one in-between...only the old guard had left a bunch of Superman robots in charge of defending the Earth and what-not, so the post-Crisis characters were depicted as either pointlessly training for the day they're needed that will never come, or as becoming shallow, directionless, social-media obsessed celebrities. Who needs actual heroes when you just have some Superman robots?
Anybody who thinks that the current regime at DC would ever earnestly and sincerely pursue 'an "Earth-2" treatment' to allow the Teen Titans and other characters to "stand in the sun" is being overly generous to said regime, IMO.