The event is ended. You can't get any more Christmas things. The zone still exists for some unfathomable reason and that's what's confusing you. If you were to leave the Christmas zone then you would never be able to get back since the event is over. Nothing Christmas related is going to appear from any bushes anywhere. p.s. you didn't have to whack in those squares at all once you completed the jigsaw puzzles there, i.e. I whacked in the lowest level square since I need to whack 30,000 beasts for another achievement.
If I had known that the zone wouldn't disappear then I would have stayed there, it would've been fun whacking icy bushes till July or whenever, probable next Halloween since that event has its own zone.