It means you are leaving the world of Ackerly Green.
Elsewhither is where all “out-of-world” content will live. We want to have a completely immersive experience here at “AGP” but we also have ideas for content that might break that immersion, such as CJ’s old vlogs, collected Publisher’s Diaries, and The Making of The Monarch Papers podcast. Anything that mentions Ackerly Green, characters, events, or objects in the MAGIQverse as “not real” is now considered Elsewhither. We want that kind of content tucked away without being completely hidden so you would have the choice of experiencing it or not. So any time you see that word you know it’s going to lead you somewhere outside of this world.
CJ Bernstein and Ackerly Green’s social media accounts are also considered “Else” though we may in the future have accounts that are in-world. There will be a clear description in those out-of-world accounts.