Even though that is pretty much part of canon, the entire concept you have proposed there (stagnating language and society for 14,000 years) is in itself ludicrous.While our own perceptions of 14,000 years ago are fairly limited, mainly confined to what tool cultures people were in and what they were hunting or gathering, I could see as Star Wars universe knowing a bit more about their past. Unlike real life where writing hadn't been invented 14,000 years ago and languages have been rapidly changing since then, basic has been in use for a while nearly unchanged and presumably, there had been some method of digital data storage which should enable people to read the diaries of people 14,000 years ago. So while they certainly wouldn't be common knowledge, our characters this time should be discoverable by those in the next timeline.