I've had experience holding onto games that are no longer sold, and from my limited number of cases, that "discontinued" price spike never seems to occur and card just becomes unmarketable with no trade activity. I suspect it's because demand also dies off with supply (since people buying the game are where most of fresh demand comes from).
Perhaps DuckTales will be different though, because of its name value.
I have like 30 cards taking up space in my inventory that are no longer marketable, from stuff like Transformers, Reservoir Dogs and even a foil.