There's very little they can say directly, even when they're willing to. Sun told Naoto they've 'enlisted our help,' and he's the reason we know as much about the causes of death for the dead Trumps as we do - there was also a difference between 'caused the death of' and 'claimed the life of,' but I can't remember which Naoto said was which.

We don't know exactly why they've pulled us in, or whether the Travelers would count as 'internal affairs' or not - everything to that end's been a lot of 'pay attention and you can figure it out.' There are messages to be had in Liminal Space, but the clearest one by a long shot that I've seen has been Junes Hell. The back shelves of the market space had stuff on it that belonged to dead people, and the other shelves were full of things associated with the dead Trumps.

We know their mark limit is five per round, and a 'round' is longer than just one jaunt, but so far the only time they've made true repeat appearances was that phone. I don't know if any of them are full up or not, but I wouldn't be surprised.

We also know ROSE wasn't supposed to take us back to the Grid, and however she pulled it off, she kept the rest of the Trumps in the dark until someone managed to get in touch with them. Whatever rules they're working by, she broke them pretty solidly, but I'd bet she doesn't care since she got what she wanted.