While not universally true, a lot of middle aged workers with many years at the bank would love to get the severance package as a bridge to early retirement or ease the transition to something new. Some managers are supportive and help that happen, fulfilling the quota with people who want to leave rather than with those who want to stay.
Just wondering, how exactly do you approach your manager if you want to let them know you would like to be put on the next layoffs list? I wouldn't mind doing that, but it seams really risky to me.