Preheat oven to 400°F.
Scoop out zucchini centers; reserve the scooped flesh.
Arrange zucchini halves cut-side up on a sheet pan; season with salt and pepper.
Bake until just beginning to soften, about 20 minutes; remove from oven.
Heat oil in a skillet; cook onion with reserved zucchini until onion is translucent.
Add garlic and cook until fragrant; add wine and reduce until mostly evaporated.
In a bowl, mix pulled pork with BBQ sauce; add to skillet and combine.
Stir in black beans, tomatoes, and corn; cook until heated through, 4?5 minutes.
Spoon pork mixture into zucchini; top with cheddar and Monterey Jack.
Bake until zucchini is tender and cheese is melted.
Garnish with cilantro and serve.