There's no other opponent of Fury that could excite us, except Joshua. We would not know who will be the best heavyweight fighter if two will not meet, it's not good for boxing and fans would not be happy on that as they only hype things out but turn out not realizing it.
The best Heavyweight is hands down Tyson Fury as he always fought high profile opponents as an underdog away from his home and yet he was able to defeat each and every one of the high profile opponents and even when Tyson returned after a few years he was able to defeat Deontay Wilder and then the judges messed up and then in the rematch he proved his worth as the best in the world.