Even though I am Pro-Pineapple-Pizza (and a lurker) long rant incoming:
It really depends on how you serve the pineapple on the pizza.
I personally think that pineapple, which is sweet-sour, meshes well with tomato puree, which is used for the sauce because tomatoes, after they are cooked, have a similar taste imo. (If pineapple is 80% sweet and 20% sour then the tomatoes are roughly 80% sour and 20% sweet.)
Anyway, I advise against cheese and the use of preserved ananas when you eat pineapple pizza.
Preserved ananas is often sweetened and if you then additionally cook/steam it, it will become even sweeter and the ananas distinct sourness will be ruined.
The reason I am against the use of cheese is first, pineapple has a certain enzyme that breaks down proteins. If you mix fresh pineapple with milk and/or it's products the proteins inside the latter will become amino acids and peptides, which in turn will give the milk (products) an unpleasant bitter taste. You could avoid this by using pre-cooked/steamed or preserved pineapples but with that, we would be back at problem number one.
Second, considering that conventional pizza cheese always creates a slight fat layer, while pineapple is often watery, it will turn into a "swimming" pizza. ( Because water and fat/oil don't really mix that well).
Third, I know a lot of people who have problems disgesting acid-rich and fatty food at the same time. So this combo can easily end in a stomach ache for some.
In the end, my personal recommendation when it comes to eating/trying out pineapple pizza would be:
- Don't eat it frozen pizza or from bigger pizza chains because of the amount of cheese and it's very likely the use preserved pineapples. Rather go to an Italian restaurant of your trust and choice.
- Make sure your pizza/tomato sauce has a nice amount of traditional herbs (i.e. oregano, garlic, pepper, ...), so that the pizza doesn't turn too sweet.
- Ananas is also known to help with the digestion of meat (because of the same enzymes mentioned above). I would advise adding Pancetta (arrotolata) o.s.. It's an Italian bacon and is normally slightly salted, which
creates a nice contrast between the sweetness. Also because it's sliced thinly it won't turn as fatty as e.g. salami, while at the same time will stay juicy.
- Add arugula. Fresh arugula is known to be bitter, as such imo it overall balances the pizza and brings the ingredients together. (Also good for those that aren't fond of "too much" sweetness.)
Ingredient summary: Traditional pizza/tomato sauce, pineapple, pancetta (arrotolata), arugula.