I don’t know. Could be there will be in-game actions that will unlock the other items, but given Emily’s “goodbye” yesterday I think it’s safe to say we haven’t seen the last of her yet. Yes we have the “it’s over” email, but I could see HG opening a new ARG or continuing this one later if they have a another major update rolling out.
I could also see her popping up time to time with more information, or hints, about the game. Last night I was thinking we would see Emily pop up this weekend saying it’s not over but given the interactions elsewhere with WT taking comments/answering questions, I doubt that will happen now