I guess who the publisher is kinda depends on what they reuse from the cancelled game, which (seeing how MS wanted to publish it) I assume was a 3d game rather than isometric- I can see a lot of publishers that would want to publish one, but maybe not the other.
In any case, I am excited to hear more- Obsidian is an amazing developer, and the cancellation of their Xbox One title was very sad news at the time...