I’ve never heard of Epic demanding a timed exclusive - that doesn’t seem to make sense given they still have minority of the user base relative to Steam. Pretty sure all exclusive periods are based on Epic making a payment to the developer for exclusivity rights.
Epic is not really in a position to demand anything since they’re still the smaller store and our deal to bring Grim Dawn to the Epic store has no connection to any other project we’re working on. At this point, I’m sort of doing it for experimental purposes. We signed a distribution contract with Epic a while back for GD and it will be added to the store… when I get around to filling out some info and emailing it back to Epic… soon™.