If it is not a factor having aircraft misplaced, then why did it take VA 24 hours or so to get things back on track post the Sabre failure last week? By their own advice it was because of aircraft out of place along with their crews. I've dealt with plenty of aircraft out of place due to cancellations and support empty ferry flights, so I'm pretty sure I know what I'm talking about.
Very simple answer to that.
The Sabre failure was a sudden, unexpected fault that prevented departures network wide. Instant chaos, and duty time issues probably run into the equation with restoring operations.
I'd say airlines have major port lock down now as a contingency plan. A single port lock down like Melbourne being knocked out of the system, with forewarning, would be a simple event, where ops would have a plan of action that will avoid what you are saying. Headache for ops for a day or so, no one is going to be stranded etc, a significant weather event would have more effect. A day of operations is a controlled event, so if all planes fly, they wanted that, if they cancelled then that is what they wanted.