In the 15 years we’ve been going we’ve only been upgraded once, standard room at CBR to Savannah View at AKL, but that was because they overbooked the category and put us in a pirate room instead but the CM realized it was our anniversary and only 2 adults so sent us to AKL but this was the one and only time. Most of the time if you are upgraded it’s either due to overbooking or some other work, with just the smallest few upgraded just because. The upgrades also have nothing to do with whether you do online check in or not. I would not go expecting to be upgraded because if you aren’t you’re setting yourself up for disappointment, go not expecting anything and if it happens wonderful and if not that’s ok to. And the worst thing you can do is ask for an upgrade, count on having to pay if you ask for it.