This would only be the case, if they choose to leave the Mo’anha Islands, for selfish endeavours - to seek a life outside of what they've been offered within the Dralic Islands, for example. 

This doesn't mean that a Soulless is then unwelcome to return to the Mo’anha Islands to visit their families or Trade among their people. But once they're considered a Soulless, they're no longer privileged to step upon the Aloha Islands, (the Central Ritual islands), for any of the Dralic's sacred traditions such as the Mating Season or the Provings. 

Becoming a Soulless means a Dralic has disconnected themselves from their element, whilst they still maintain their abilities - they're no longer as strong. 

If for example, a Dralic is ordered to leave the islands for any large purpose that would benefit their Clan, or complete their Proving, then they are not considered a Soulless. 

Only when they choose to leave of their own accord, to seek prosperity outside of their Clan Islands, are they then considered Soulless. 

There is usually a Ritual given to those who choose to leave - they are sent off with supplies and a boat to carry them to the mainlands. Their faces marked with a band of Red paint around their eyes or a red 'X' across their Marking if they received one upon completing their Proving. 

This is an old tradition performed and passed down by the Elders.