After Becca has died Mitchell is in a big shock. He wants even more to live a normal human life and leave all the things that are connected to vampires behind. So he organises a neighborhood meeting. Without telling George about it he invites all the neighbors to their house. Mitchell says that they need to dive into the churn of humanity. Laugh with them, listen to their stories. It is also possible that Mitchell wants to send a message with these meetings. He knows that the vampires of Bristol are organising and he wants to show them that he does not want to be part of it. He also wants to show them that they can live normal lifes together with humans and that they do not need to take over the world. (see the quote at the bottom)