Yes, we were there last week and that was the case. It was pretty strict! And for a pool that, while nice enough, wasn't anything special compared to other pools on site. Interestingly, BLT and CR are "sister" resorts (BLT is the
DVC wing of CR). But although BLT guests may use either the BLT pool or the CR pool, CR guests cannot use the BLT pool. So it's possible that AOA and Pop might be "sister" resorts and share certain amenities, but still restrict access to the Big Blue.
Frankly, I think it's perfectly reasonable to restrict access. AOA is a lot more expensive, and with not getting discounts, they should at least have easy access to their pool!