I assumed that if Cobel went with them, she would definitely not be talking to the board and would definitely either be killed or end up owned by them and experimented on like Gemma, never to see the light of day again. She knows too much and is too much of a loose cannon at this point, and Lumon doesn't seem like the type to just calmly acquiesce to her demands. The board just happened to be immediately available to speak to her? Ok. (Also, I think the board is either some AI entity or the digitized consciousness of Eagans who are now dead and gone. Just a side note.)
In all the mail they've shown throughout the series, the address is Keir, PE. I think they are in the US, based on the question they ask about it when innies first wake up, but definitely in their own...state? Municipality? Or is the entire thing a simulation?
I do think reincarnation or at least the saving/resurrection of consciousness is the end goal. Helena's dad talked about seeing her at his "revolving". Obviously Gemma is still around in some form. Last season, Cobel's shrine involved her dead mother's hospital bracelet - maybe she wants to bring her back and that's one reason for her devotion to Lumon.