Really stoked about this!
Funnily enough, Marvel is planning something similar and when I read about it earlier this week, I couldn't but help wonder that it would be a good approach for DC to use the same kind of overarching generation-spanning story structure to explore their new timeline. And now...lo and behold!
Obviously, they're really delving into this question of who was the 'first' superhero - something debated a LOT on this forum but which has rarely ever been addressed in the stories themselves. The JSA retirement story is obviously being rewritten given how, in the new timeline, they apparently disbanded in the mid-50's rather than in 1951. The Golden Age hero who'll become history's greatest villain is an interesting one...Terry Sloane seems like a safe bet given that he had a similar role in Robinson's Earth 2, but I guess it could be Spectre. I wonder if the villainy in some way pertains to triggering the cycle of reboots and resets that Manhattan talked about in DDC.
The Wayne family dynasty bit interests me the most. Alfred and Lucius are part of this, so I have a feeling this might involve them. I wonder if this ties into the Court of Owls somehow.
On the subject of the miniseries names - Age of the Metahuman seems an odd choice for the Silver Age book, since 'metahuman' is more of a modern term that wasn't really used back then. All the other names fit their respective eras perfectly.