Like wars erupting over FTL rather than sharing it, because the country or a corporation who would be the first to have such technology stands to have the potential to colonize distant planets.
There are so many good literary possibilities with this. Imagine a ship of older such types sent to a distant planet. They not only start de-aging during the journey but also losing memories to the point where a bunch of very confused young people arrives at a distant planet where their most recent memory is fighting with mom & dad over being able to drive the car and no idea how/why they're on a habitable but distant planet