Well, something WAS happening today (even the flight status functionality on aircanada.com was malfunctioning today), but I am not sure if meltdown would be the right term... Maybe just a streak of bad luck.

The multiple threads you have mentioned pertain to quite likely multiple, distinct and more or less independent systems. These are also systems in two quite separate IT departments (AC & AP have separate IT ops, right?). So, sloppy coding/testing? Yes, quite likely. Some bad luck? Possibly. Meltdown? No sign of it.