Combine 1 Tbsp. barbecue seasoning and 1 tsp. salt; rub evenly over pork roast.
Stir together tomatoes, next 7 ingredients, remaining 1 Tbsp. barbecue seasoning, and remaining 1/2 tsp. salt in a 5-quart slow cooker.
Add roast; cover and cook on LOW 9 hours or until meat shreds easily.
Remove roast; remove and discard bone. Shred meat using the tines of 2 forks. Return to slow cooker, and stir together with sauce; spoon over multigrain buns.
Serve with pickles, if desired.
Note: For testing purposes only, we used Chef Paul Prudhomme's Magic Barbecue Seasoning.