Here is a case where the position I have argued for seems to be uncontroversially true. Consider
(A) The earth was created around 6,000 years ago.
(B) According to the Bible, the earth was created around 6,000 years ago.
Fundamentalists will say that (A) is true, non-fundamentalists that it is false. But both agree, indeed everyone who is familiar with the Bible agrees, that (B) is true. According to the Bible, the earth was created at a certain point in human history.
In this case, no one is tempted to say that the Bible is about some parallel Biblical world, such that all the statements in the Bible are by their nature true of that parallel world. On the contrary, both fundamentalists and non-fundamentalists agree that the statements in the Bible are about our world, and that (B) is not a statement about some Bible-world, but about what the Bible says.
Given the existentially conservative explanation works in this case, what reason is there to suppose it should not work in the case of fiction?