Pineapples are harvested ready to eat. The sweetness level isn't going to increase dramatically. You can't always judge a pineapple by its cover so it can be tricky to know which ones to pick up - you see the Dole and Del Monte label everywhere.
At one time the majority of pines did come from Hawaii but now it seems everyone has headed south, way south, to Costa Rica. One brand that I have first hand experience with is "Linda Gold" - it is not a big brand but rather a artisan brand. One grower with four different planatations in Costa Rica which allows the grower to take advantage of different weather patterns (and also it offers him protection should one area not grow as well as it was suppose to.). The brix level is normally at 15 to 16, the colour is a deep yellow and the taste - well, it almost seems like they added sugar but they didn't - this is the way they are suppose to taste.
And speaking about adding sugar - one of the worst things to hit a produce department, in my opinon, are the "Grapple" - apples that have been injected with goodness knows what? If I was running my own produce department those would not be crossing my threshold. There's enough obesity out there without encouraging practices like this!