Not because of the fructose, but that may also be a problem. I'm not a great cook but I think that Angel Food Cakes are one of those fussy things and they don't normally have sugar so I'm just guessing that the sugar may mess up the cake. Anyone who is a better cook please confirm this. I'm not sure.
As for the pie fillings, your guess is as good as mine. If it's full of high fructose I would avoid it. If the ingredients seem wholesome, you might be OK. I would say you're better off making your own pie fillings. Blueberry pie is as easy as a wink and only contains a little margarine, flour, sugar and salt. You can easily make your own. Put in a graham cracker crust it's quite yummy.
Blueberries and cherries are bothersome because of their skins, but if they are cooked in a pie they are easier to digest.
If you're looking for ways to incorporate fruit, you can always puree them up and cook them with some other stuff to make a nice sweet topping for pancakes, etc.
Hope this helps. I didn't really have answers for you.
Formerly HanSolo. IBS, OCD, Bipolar, PTSD times 3.