As I mentioned earlier, separation between student pilots and commercial traffic could become a safety concern justifying the need for a tower.
"The bulk of that traffic is coming from a 180-student flight college that's training pilots for airlines in China. But the airport has also seen considerable growth in the number of commercial and private flights."
http://dailygleaner.canadaeast.com/article/723604
Actually my sarcasm/smile is over the use of the term International in the airport name, and yes it is legitimate. But the best I can tell is traffic consists of Air Canada, the flight college and charters to the Caribbean.
I used to fly out of a small airport which like many in NB is near the border.
One weekend the airport operator had a fly-in and of course some recreational pilots came over from Maine. Sure enough the fly-in all of a sudden became "International."

When I was in CFB Baden we would have aircraft from the US, Germany, France, Italy, England and Holland fly in for an airshow.
Now that was an International Airshow. 8)