Malic acid is very difficult to destroy and survives most processing but logic tells us that its must degrade each time it goes through a process. Even cider contains malic acid and that’s apple juice which has been highly processed. Basically the closer to a real apple/cherry it is, the better the malic acid content. But even apples vary greatly in their malic acid content. Green sharp apples like Granny Smiths are the best.
If the juice made from pulp then you will probably need to drink more. Sour cherry juice contains 5 to 6 times the malic acid content of apples; so, I assume it to be the better processed juice to drink.
Apricots, peaches, grapes and rhubarb are also high in malic acid, about as high or higher than apples.