Well, i think some kind of pre-text would be lovely.
I dont think "the old world sank in chaos and ppl had to leave their homes to be able to stay alive" crap would suit this game.
Personally, i think it should be more like:
They heard rumors about an virgin land, untouched by humankind.
A retreat from servdom, from landhungry lords and Kings.
A new beginning across the ocean.
(Which could be used as an Intro-Video if some starts new)
Or somethin along such lines.
Which WOULD give th opportunity to some Kind of Events, like the old kings want dominion over the new world too, and the community has to fight them off or such (IF and only IF such things will be considered before the public release).
But i think, the lore will go on. There are bound to be ppl recording the major events, like wars etc.
I think pretty much every bigger guild will keep their own records in one or another way. But i think it would be a nice idea, to have some kind of library, (fixed building where can add Scrolls/Books when you got to status of a Kingdom//Town) which will get added to all other Librarys. So there is some kind of knowledgebase there, to share the historys of the guilds and kingdoms. And of course, share it for longer then the kingdom might be alive
(Might be able to get abused to simply transferring messanges, so might add a fee if you like that idea, [i already have in mind, that there will be a currency])
Anyway, after the initial "why did we go to that new continent" it should be as free from prewritten Lore as possible.
Maybe an event or two, that would be fine, always keeping the circumstances in mind.
Well, thats my 5 cent to this topic =)