NO, AA could swap aircraft around. It's not at all clear that the flights that were ascheduled on MAX 8s are the flights that will be cancelled. Moreover, in the end I would expect to see a fewer total number of cancelled flights than the total number that were scheduled on MAX 8s. AA will rearrange aircraft schedules and use their equipment more intensely. They'll prioritize flights/routes to keep and which ones can be cancelled with minimal impact on profits.