The thing is Atlanta doesn't have to trade for Hayward. They could outright sign him in FA anyways.
Yes, but the starring contest is that Hayward wants to go to Indiana. The Celtics could bluff that they are trading him to Indiana, and if the Hawks want him, then they need to pony up now.
If I were the Hawks, I'd be targeting Bogdonavic anyway. I think that's the reason why the Kings were unable to convince him into a sign-and-trade with the Bucks.