They had a handshake agreement that he’d be allowed to leave if a big club came calling. Enter Juventus. Of course to save face with their rabid asshole fans (like the rest of Italian clubs) they’ve created this big song and dance, made him miss the majority of the pre-season with us. But in the end, he’ll sign with us and hopefully on more favourable terms.
Clubs who go back on their word to players are never looked on favourably by players/agents, so Atalanta know if they play hardball and try to keep him they will burn a lot of goodwill. This is the game.