Are there actually any QF mainline flights that are in the 200 range? On a very unscientific search, I could only find flights that were ops JQ (or maybe they were AO). I wonder if anything could be read into that?
Or maybe a temporary flight number just assigned for planning purposes? (Said in a fit of wild speculation.)
I can't think that the frequency or seasonality of the route would necessarily lead to this. For example, take QF107/108, which is daily to LAX but 3x to NYC.