Hi,

Try the below code to inherit the sale.order function action_confirm and select the users.

          @api.multi
          def action_confirm(self):

              return_value = super(sale_order,           
       
      self.with_context(mail_create_nosubscribe=True)).action_confirm()

              for follower in self['message_follower_ids']:
                  follower.unlink()

              return return_value



Thanks