Quests 5, 10, 25 and 38 all had "Exchange X items in the Antique dealer". If you haven't unlocked AD yet, you can't do that. But these quests will NOT autocomplete. They are all OR quests that can be completed without AD.
The same is true of the quest the OP is worried about. It has an alternative that doesn't require access to GE, Defeat a large army. So, the event can be completed at the OPs stage in the game. It may be very difficult, due to lack of troops, atk bonus and skill, but quests don't autocomplete just because they might be too hard for someone.