EUREKA#10:O Little Town/Season IV/2010

[Rabulias]

Yeah, I don't think either episode fits in chronologically with the previous episodes. They were Christmas specials.

The Eureka special clearly takes place in the alternate timeline (Fargo is the head of GD, Jo is GD Security Chief, etc.) which was created after Zoe went to college, and has only existed for a few months or so.

So if this is canon, it looks like the alternate timeline will not be undone (at least not for a few years). Of course, it could also be that Jack and the others could get back to their timeline and this one continues on its merry way...