They cancelled your landing clearance, not your approach clearance. The intent is that the departing traffic will be clear in time and they will then reissue your landing clearance. If for some reason it gets too tight, they will then tell you to go around.
On a related note, I finally visited the Mighty 8th Air Force Museum in near Savannah, GA this week. Well worth a couple of hours if you are in the area.
As a teenager who got there private pilot certificate around that time, I liked Iron Eagle. II and III, there’s no excuse. :)
Edit: Just looked it up, I was 21 when Iron Eagle came out, so I have no excuse. Still liked it. :)