My guess is Helen Beckitt doesn't know. However, she's smart enough to notice that Marcone has stopped aging and motivated enough to find out why. Gard might or might not know. We don't know how much Odin communicates with his vassals and Gard was guarding the meeting of the supernatural members of the anti-Fomor alliance, she was not an attendee. However, someone like Gard would have to wonder how Marcone survived his encounter with a Titan. She should figure it out sooner or later, and probably sooner.
Think of all the players who were at the meeting that Harry interrupted. Lara Raith knows and now knows to be extra careful with Marcone. Sarissa knows and I think this is something she would probably have to report to Titania, though I bet she wouldn't tell Fix unless it's information he needs to know.
I wonder whether anyone will be motivated to spread knowledge of Marcone's new business partner around. I would think that if only as a curtesy Harry would mention it to Butters and Sanya, even though Waldo may already know. If Harry was still a member of the White Council he might have informed Carlos, should the younger Warden ever come to town again. Now if Warden Ramirez does come back to Chicago; even if only to issue Harry a warning from the Council, Harry doesn't have any motivation to give him any warning about Marcone.
