does mcdonalds still sell wildberry smoothies if not why were they discontinued?

Not anymore

It might just be a seasonal item for the summer when the fruit would be in season.

McDonald often tries new menu items to see how well they sell. If interest in a product drops, they will remove it from the menu because it is not making money. Some items, such as the McRib they offer occasionally because studies have found people like to try it, but then go back to their usual orders.

Wildberries went out of season

no they don't. they're discontinued probably because they didn't sell a lot of them

I don't think they have those.