I think this is actually wrong. It certainly doesn't hurt to write on fired clay tablets, or to "store" your papyrus documents in an extremely low-humidity environment. That might enable accidental preservation. But at the of the day (or at the end of the millennium), things survive because lots of people care about them.
You mention Anglo Saxon. That's an interesting example, because the entire corpus of Anglo Saxon literature is easily anthologized in a single volume, and there is exactly one extant copy of what most scholars regard as the most important thing written in the language (Beowulf). But the truth is this: Most of it is gone, because people stopped caring about what was written in it.
But psalters? Bibles? Church histories? It's an embarrassment of riches. Why? Because people cared very deeply about those things.
And translation helps, but again, it's not quite enough. The instructions for my dehumidifier are in eight different languages. Where did I put that again?
To come at it from another angle: Finding a paper copy of a 1955 Seattle phonebook is extremely difficult. But why? It was written on paper, there were thousands and thousands of copies printed, none of them have actually disintegrated into dust, and yet . . .
So: My advice would be to make that web page pertain to something of epochal importance to millions of people. They'll do the rest.