This story has been visible on the internet, but likely no more because I cannot find it now with search engines despite a considerable effort. Written in English in 2017 or 2018 (or possibly one year off forward or backward).
The only occupant of a starship from Earth awakes (presumably from hibernation) and listens to a repeated voice message (probably about approaching the target). He soon finds out that the target planet, unexpectedly, is home to an advanced civilization. The local sentient race looks just like humans, but they decline to identify themselves as humans and use some fancy name instead (like “Cetians”, but I cannot remember it exactly).
They tell their story: billions of nanoprobes sent from the Solar System (via space) assembled to an AI which, in turn, constructed all means necessary to produce several sentient individuals. Those individuals (which, again, look completely humanoid) reproduced naturally afterwards and built a civilization. They maintained radio communication with Earth for some millennia, but some eleven thousands years ago a message from Earth reported strife (presumably a world war), and Earth transmitters went silent. Local Earth experts consider humanity extinguished, or reduced to a savage state (as a minority opinion).
Obviously the man considers staying on the planet a natural option, but when he tries to court a local woman, she rebuffs him: intercourse with Earth men is not permitted. Genome of the locals is engineered, and they disapprove raw human genes anyway. The frustrated Earth man departs to his starship, having intention to hibernate for some hundred years.
Unfortunately I forgot name of the character, cannot remember neither title nor any clue about the author, except that the story won some minor award.