Meh, the replicants of the Maxim 39 crew won't be the same as the people on the ship for it's last few seconds/minutes/hours. But they're indistinguishable from themselves from a week before. Are you a fake if you get really drunk and totally forget what happened to you last night? Those memories and actions are all gone after all. To continue with the analogy most anyone would choose to go on living even if he knows his last few days' memories will be wiped. Deleting random parts of their memories and personalities is a tougher question but still many many people choose to live even then.