Interesting. It's possible that
DVC has something special in mind that's coming soon, but APs DO NOT go on sale once a year. They certainly have NOT in my experience. In fact, there's usually been a yearly INCREASE in AP prices. I'm actually expecting any deals on APs due to the opening of SWGE. We'll see, I guess.
FWIW, keep your 60 day mark to make FP+ reservations in mind and buy your passes in time to do that. Otherwise, unless you think the price is going up soon or if you need to buy several APS and want to spread the purchases out over several months, there's really no need/advantage to buying them too early.