ETA: I posted this also on the top of this comment thread, so you can answer there if you wish.

The way I read the quote is:

A proposition being true doesn't mean that it has the probability of 1. It does however mean that if a proposition is assigned a probability of 0.9, and it coincides with what the world is actually like, it is true.

This in turn could be read as:

A proposition being true doesn't mean that is has the probability of 1. It does however mean that if a proposition is assigned a probability of 0.9, and it coincides with what we know about the world with probability of 1, it is true.

Do you now understand my objection? I predict it's based on some grave misunderstanding. Thanks for the link, I'll try to check it out when I have more time.