An email I received from GO today:
On Wednesday March 7th, Raptor basketball and TFC soccer fans can leave your post event travel worries to us.
To get you home after the evening's events, in addition to our scheduled hourly service, we will operate 2 extra trains: one westbound to Aldershot departing Union at 23:13 and another eastbound to Oshawa departing Union at 22:43.
We hope you enjoy your evening event and have a safe ride home with GO Transit.