Preheat oven to 450 degrees.
Pour 2 Tbsp olive oil, red wine vinegar, garlic and herbs into a gallon size resealable bag. Add chicken, season with salt and pepper then seal bag and massage mixture over chicken while working to evenly distribute herbs. Set aside and let rest while chopping veggies.Place sweet potato, Brussels sprouts, apples and shallot on an 18 by 13-inch rimmed baking sheet. Drizzle with remaining 2 Tbsp olive oil then toss to evenly coat, season with salt and pepper to taste. Spread into an even layer.
Set chicken thighs over veggie/apple layer.
Separate any pieces of bacon that may be stuck together then sprinkle bacon over veggie apple mixture.
Roast in preheated oven until chicken and veggies are golden brown, about 30 - 35 minutes (chicken should register 165 in center). Broil during last few minutes for a more golden brown crispy skin on chicken if desired.
Garnish with parsley if desired and serve warm.