If you accept what Doomsday Clock says about the New 52 Earth zero becoming Earth 52, then you should also accept what it has to say about the pre-crisis Earth One and the Golden Age Earth 2. All I'm doing is taking that and putting the Earths that Doomsday Clock described in context: the “Earth 52” that Johns named exists in the context of an Orrery of Worlds that also includes the Earth 3 seen in Forever Evil and the Earth 2 seen in the eponymous series, both of which involved significant interactions with “Earth 52”. So I'm inclined to call “Earth 52” the Earth 0 of a “New 52 Orrery of Worlds”, which was outlined in Morrison's Multiversity — because that's what the Multiverse was at the time.
Likewise, Johns' “Earth-1985” and “Earth 2” are basically the Earth One and Earth Two of the pre-Crisis Infinite Earths. At a minimum, the other Earths they interacted with (the preg Crisis Earth 3, Earth S, Earth X, the homeworlds of Lady Quark and Pariah, Earth 4, and Earth Prime) should exist in the same “context” as them.
Finally, the last issue of Death Metal stated that not only was the Multiverse restored (with changes), but universe and even multiverses beyond the 52-world Orrery were coming into existence. It's possible that at least some of these new multiverses are old multiverses reborn — likely, even, given how the creators' intent was to make everything available to the writers going forward.