Preheat the oven to 350°F and grease a 9x13-inch baking dish.
Bring a large pot of salted water to a boil and cook the jumbo shells until al dente according to package directions.
Drain the shells in a colander and rinse briefly with cold water to stop cooking; set aside to cool enough to handle.
In a large bowl, combine the chopped rotisserie chicken, taco seasoning, room-temperature cream cheese, sliced green onions, thawed corn, salsa, and ½ cup of the shredded Mexican cheese blend; mix until evenly combined.
Stuff each cooled shell with the chicken mixture and place them seam-side up in the prepared baking dish in a single layer.
Sprinkle the remaining 1½ cups shredded Mexican cheese blend evenly over the filled shells.
Bake for 15–20 minutes, or until the filling is heated through and the cheese is melted and bubbly.
Garnish with sour cream, halved cherry tomatoes, and fresh cilantro if desired, then serve.