It seems like regardless of who the tasks are assigned to, you get email notifications that the next task is ready to start.
It would be great if Projects with multiple assignees could use the Wrike Bot feature to let them know when the tasks above the one assigned to them are all complete and its their turn. Instead users are alerted when they finish a task and they can do their next task. Honestly, they are already logged in and working so these are redundant.
Maybe I'm missing something, but all of my users have turned this feature off as they don't find it helpful.