If you and others were added shortly before scheduled push time, one theory is that the gate was working off a "before" and "after manifest".
Not sure that ignoring status is right here. Clearly, the right thing would be to cater to 100% of J seats in case of irops. Heck, Air Canada often has a way to sell the extra meals to Y passengers.
I wonder what would have happened if you offloaded yourself due to the service failure....
$30 vouchers are way too easy for them to print and send you on your way. Maybe you could ask for a signature service meal brought from catering and served to you in the MLL.