@maisonaustyn possible spoiler because you're skipping ahead. Even in the novels this didn't happen immediately, it happened later after ChaeIn recovers and finds an opportunity to talk to JinWoo.
There are things the US can offer any hunter to entice them to move to the US, in particular they have two very large cards they can try to tempt them with. I won't say what they are though.
Dang, he dismissed the healer? Seemed like a pretty valuable asset, but also I suppose it is a good thing to do. Then again, that one other hunter probably didn't want to be a shadow either.
Part of me wonders if he was just pretending. Seems likely. Not actually looking to be spoiled, mind, just speculating.
@Fari I mean, all he said was cancel summon and all. It sounds more like a command to put it away, not to remove it entirely from his saved shadows. I guess we'll see eventually either by his presence again or his absence for however long there is until the end.