When your fortress reaches a certain level of prosperity, a new option could appear below abandon, the option to send out 7 dwarves to create a new fortress. You would get to choose any 7 non-noble dwarves from your population and any amount of supplies. The weight of the supplies you could send would be limited based on how many wagons you can create and what pack animals you have to pull the wagons. If you choose this option, then when you start your next fortress you skip the swarf set up screen, you only need to choose a site from the world map.
This option would give players a new goal to work towards that would reward good playing. The only problem might be that starting a new fort with all legendary dwarves would make starting the new fort too easy, but I think that would be okay because you need to work hard on your initial fort to get this reward.
