Why was it imperative that papa and Mr. Morrison be talk about what had happened at the Avery home ?

I'm not sure about the first part of your question. Areyou sure it is in chapter 11? Kaleb and Thurston Wallace and RW and Melvin Simmssmash their way into the Avery house and violently drag out its inhabitants. They break TJ's jaw when he emerges. One man holds up the gun, saying that RW and Melvin saw TJ and two other boys running form the Barnett's store and demanding the money they took. Kaleb kicks TJ in the stomach, knocking him down, and throws Mrs. Avery back against the house when she protests. Mr. Jamison arrives in his car and tells them to take TJ to the sheriff.