An epic confrontation that requires two GLs. Now that's a scary thought.
Though I don't see where it would make that much money. The requirements for GLs are already relics. So those that whales on them will already be ready or close to it. Those that didn't get both will likely be too far away to be worth the whaling.
Sure there's some I the middle but I just don't see it.
More likely we'll get a surprise mando marque followed by a legendary. Since most people were distracted working on GLs and probably haven't geared the new mando characters yet.