I don't know much about the OHL, or where Flint is at in terms of their cycle; But I am a QMJHL fan and see this stuff happen all the time here as well.
I think Flint probably had a good idea there was a 75-90% chance McLeod would not report, however the way it worked out, they ended up with 3 second round picks, 3 third round picks, plus the 5th overall in 2016 as a compensation pick from the league. (Correct me if I'm wrong).
I imagine they are doing what Cape Breton did a couple years back with Nicholas Roy, picking the player knowing he probably would not report, than trading him for a ransom and taking the compensation pick. 3 years later Cape Breton is poised for a run at the league title.
A note of interest tho, the Q actually got rid of the compensation pick if you trade a defected player after this incident, as Cape Breton ended up with 3 1st round picks and former first round pick Loik Levellie in the end. (In the Q you can trade your 1st round picks, unlike the OHL.)