Aune writes this in his commentary about this language at this particular point. He says:
The motif of a Book of Life in which the names of the saved are written and the motif of the erasure of a person’s name from such a Book are extremely widespread in the OT and early Judaism, sometimes used together and sometimes separately. The possibility of having one’s name erased from the Book of Life suggests that fidelity to God rather than any type of predestinarian system is the reason for having one’s name inscribed in the Book of Life in the first place (see Rev 17:8).
I’m going to read that over again. Because we tend to read these things as though, “Well, God wrote all those names in there beforehand, and once they’re written, God can’t unwrite them. He can’t erase them.” In other words, it’s this confusion with the concept of election that divorces election from believing loyalty. And I’ve commented before that I think election in the Old Testament is fundamentally misunderstood. Israel was elect. No kidding. Duh. That’s very obvious. It’s just too bad that a lot, maybe even most, Israelites you’re not going to see in heaven. Why? Because there’s this thing called the exile—a grand apostasy of the elect. And then you have the non-elect (those who aren’t Israelites) being grafted in. Well, how does that happen? If everything’s written in these books beforehand, how can that change? Again, what Aune is saying is it’s wrong-headed to think of this in predestinarian modes because things do change. Okay? [laughs] The non-elect become elect. The elect go off and worship other gods. And they’re out. Okay? Things change. We have fundamentally misunderstood this idea.