Really the generation ships associated colonies don't even need a singularity to be sufficiently divergent to be interesting, they were isolated communities for a thousand years, a thousand years ago in the eleventh century is when the manuscript for beowulf was written in old english. While we are speaking modern english here, one thousand years evolved from the contemporary english of the scribes who wrote that manuscript, it sounds NOTHING LIKE our modern english, check this video of the olde english manuscript being read to see what I mean, and bare in mind that was written as far back from now, as the generation ships launches were from current in game date.
Source: https://www.youtube.com/watch?time_continue=7&v=_K13GJkGvDw