Soak 8 short bamboo skewers (or assemble 4 long metal skewers). Trim excess fat from chicken thighs and cut into bite-size pieces, about 1-inch cubes. Place on plate and microwave on high for 5 minutes, stirring once halfway through. Cut bacon crosswise into 2-inch-long pieces. Thread skewers, starting with chicken, bacon folded in half, pineapple chunk, bacon folded in half, repeating until all ingredients are used.
Prepare grill with medium-hot coals or heat gas grill medium-high. Place skewers on grill and cook 6 minutes; turn and grill 6 more minutes.
Meanwhile, stir barbecue sauce and pineapple preserves together; heat a minute or two in microwave to warm. Microwave cooked rice following package directions.
Remove skewers from grill. Brush with warm sauce. Serve over rice, with extra sauce on the side.