According to Wikipedia, Playground Games is an independent studio. Ralph Fulton, head of PG was formerly a designer for Codemasters for the Dirt, F1, and Grid series (see his LinkedIn profile). If I had to guess this is a new IP. Pretty sure they mentioned that earlier this year, and they've been working on it for a while. Whether it will be revealed in 2018 remains to be seen. I highly doubt it would be a Fable game after the failure of Fable Legends. That would be a lot of resources to a lot to a Fable project right now IMO.
-k