What is Counter-Earth?
For those wondering, Counter-Earth is basically the Heroes Reborn Earth, minus all the heroes, pulled into our universe and orbiting on the opposite side of the Sun from our Earth. To my knowledge, it was last used in Thunderbolts, where the team had become saviours of the planet and were basically fixing all the planet's problems for them. They ended up leaving Jolt behind on the planet, who went on to join the Young Allies, who are led by the same Bucky in the teaser image above. Counter-Earth was also in the Hyperion arc of New Exiles, but I'm not sure if that's considered in continuity or not.
Rafael Albuquerque mentions that is just a sketch he did of one of the characters in the story and that he is only a guest artist, implying that it may just be a random side story, but with Marvel promoting it, maybe she will be rejoining the Marvel Universe proper as the new Bucky to Bucky's new Captain America. Perhaps the whole time platform/Red Skull subplot was actually tapping into the Heroes Reborn universe or Counter-Earth and that's what sparks the whole Reborn mystery event. I've pretty much spelled out my theories on the teaser, Cap and Reborn, but what I want to know is - what do you guys think?