FJ,
I will concede that you are probably correct, given the way it's worded.
On the other hand, as was pointed out earlier, they hold all the cards. They know if they'll need to DRF, slightly or heavily. Given current manning levels, I don't think there's much overage out there.
If, by chance, you notice a day (Dec25 or 26, say) when # of trips exceeds max open, make the attempt to pick one up @ AVA. No vips option, call scheds and make the verbal request to put it on tape. When denied then, if you've filled the squares for being assigned an AVA trip according to the CBA, grieve it.
Good luck.