Oh. Right. I was going to mention the old multiverse debris but I didn't want to make it too long.
I kept writing and erasing and trying to simplify it as much as I could since we're talking about three writers piling lore and reveals on top of the other.
So, first, like you, I thought that they erase the concept of Metaverse, but when I looked into it, Snyder and Johns don't really contradict each other.
Johns said that every time a Crisis happened and the story move forward, the Metaverse preserve past stories in the Metaverse. Both moves on, alive. The Metaverse with old stories, the main Multiverse with the current stories.
Then Snyder said that the current characters are the same ones from the past continuity, they've been rebooted with new story every time, but they're all part of one timeline dating back to real life 1938.
So at first, I thought this is a new lore... but what Snyder said matches what King told in The Button. When Barry and Bruce went back in time and they saw their Silver Age version, they realized that they're not parallel version, but "they're us", and this is while Doomsday Clock was still in writing.
So nothing's changed. Both telling are supposed to be true. The current characters ARE the same as the past versions, reincarnated over and over, and there ARE archived old stories in the Metaverse.
So now we know what happened to the characters, and that they have archived copies, but what happened to the original earths itself? If there's a copy in the Metaverse, there should be an original.
At first I thought they reincarnated too, like the characters. Infinite Earths merged into New Earth, New Earth split into New 52 Multiverse, I thought it worked that way.
Now, in the recent Williamson's story it's revealed that the old multiverse (now named Multiverse-2) are physically there, but abandoned and in ruins. So only the characters moved on to the current Multiverse.
So that's why the Metaverse isn't gone for me: There's the physical original in ruins, there's the physical characters reincarnated and migrated to the current Multiverse, and there's the archived copies of both characters and Multiverse in the Metaverse.
Also, just found it, there's this Batman's notes from Flashpoint Beyond #0 by Johns for next April
The characters talking to Batman are those clowns from Doomsday Clock. Metaverse, Multiverse, and Dark Multiverse all exist in Omniverse.