I wouldn't call it "stealth YA/Teddy and Billy event". It was clear from the beginning that Hulkling was the key character the whole thing sort of revolved around. It's not like Marvel tried to hide it. And Billy didn't really get that much spotlight. He's only in half the issues and only showed up in one of them towards the end. He didn't really get any more spotlight than most of the Avengers like Carol, T'Challa, Tony, etc...