Ah... but that's where MY or YOUR official traveller universe comes in - players CAN change things and then, later, if they read the later-era books, know that they CHANGED that history... that in your universe, at least, they made a difference... an assassination was avoided... that ship wasn't destroyed by pirates, etc...
Of course, it can be harder for players to then shift time periods, particularly if they'll be later playing in the same, previous, timeline as they did before... all part of the fun though.
I love the richness of the background - it's moved well beyond "Well, this is what I've decided this part of the universe should look like", which most TV series, films and RPGs have, into "Well, originally I planned it differently, but someone else came up with this neat idea and we've had a few adventures develop it into this now" which is more like Greyhawk, Forgotten Realms and a few others - noticeably more rare than the previous catagory and is something that can only be earned through aging.
So much so that I feel that sometimes it seems a little... daunting to make your own universe when you see just how detailed some of the Traveller universes are - the bar is much higher than, for example, D&D, where you can start off really small and work outwards (I actually tend to work from really big, but sketchy details, down to small and then detail back the other way, so I know how the area fits). Traveller seems like the universe works slightly differently - working with sketchy details for each world, but allowing more details as you go on...
I've had a Traveller boxed set on my shelf for years... but never did more than glance at it. Now I wish I'd gotten more Traveller stuff than some of the other books in my collection... I'm certainly making up for it now.
