The Heroes Reborn dimension has missing or replacement heroes
The 616 heroes became their Heroes Reborn selves in the pocket dimension until they left and returned to 616. When they did, those heroes were either not present in the pocket dimension, or, the pocket dimension came up with replacement versions of the heroes that left. This could explain the different heroes in Onslaught Reborn, but it is not clear if that dimension is the original, an updated version of the original, a remade dimension based on the original, or a new dimension entirely.
- During the series the question, Onslaught Reborn, it was shown that Franklin created a new version of its own versions of the characters, so it's not the same Earth as before.
