orkoidSTD wrote:but this makes them a different species. and they come from different worlds. so technically they are aliens

They are no more alien than the other cultures that are still counted as "human" despite having adapted to life on the planet they colonized, such as the brutish Catachans. What
could potentially happen is that a human offshoot may be mistakenly labeles xenos because their discoverers do not yet know they were spawned from a lost human colony, though!