I don't add extra sweetener, but many prefer the extra sweetness. (cleaneatingrecipes.com)
I think coconut milk would probably work fine, but you might want to add little extra sweetener as I don't think it would be as sweet as apple juice. (deliciouslyella.com)
The fruits were so sweet I didn't need extra sweetener, but you can certainly add more sweetness if you like. (myberryforest.com)