The Waterloo Airport flight status has nothing for FlyGTA departures for tomorrow - so I'm guessing they're all cancelled flights.
I don't think we ever had confirmation that they list cancelled flights as sold out. Just our conjecture based on what we've seen happening.
Edit: Also, I don't think its a big deal for them to be cancelling flights this week. It's reasonable that demand is down and/or they don't have the additional capacity to handle vacations/maintenance work so cancel flights during down time.
I don't think we ever had confirmation that they list cancelled flights as sold out. Just our conjecture based on what we've seen happening.
Edit: Also, I don't think its a big deal for them to be cancelling flights this week. It's reasonable that demand is down and/or they don't have the additional capacity to handle vacations/maintenance work so cancel flights during down time.