Yep, you can see that at about 3:17 on the trailer.
I wonder if that would have been a story they would have told had they got a full 22 episode season? It's not really necessary to this story so they can leave it out of the 13 but if given time I'm sure they would have expanded on it. Maybe it could have been a story for a second season but I'm not sure they'd center a story around a flashback.
As I recall reading the plan once was for Wonderland to be filler while the original Once was on break, then it was given it's own slot but then it wasn't picked up for a full 22 episode season (although it feels like it with the Taste and time off for Olympics taking up a few months). I think I read the producers had said they'd tell their story in as many episodes as they got, like if they had got more than 13 it could be expanded on to fit in 22.
I wonder if the budget for this show would be too much for ABC Family? Like if this aired it as a miniseries/event type deal, maybe in the summer or something.