People tab of a project to dynamically update

Description - Right now, the People tab of a project is not dynamically updated to people actually in that project. Anytime someone is added to a task or issue in the project, they are added to the People tab (or are the PO or other reasons). But then they remain in the People tab even if they are removed from the project tasks. 

Why is this feature important to you - If users are opting into emails for 'updates about projects I'm on' then they are getting these unnecessarily. This is a big issue when it comes to projects that act as the projects receiving issues/requests - those projects will never go away as long as we have the request queue feeding it, but more people are randomly added to the project and after a while they aren't needed to be there but are still getting the notifications.

How would you like the feature to work - The People tab should be a reflection of the current state of the project, and should not include users who have been removed as assignees. 

Current Behaviour - Users are added to the People tab when assigned to a task or issue, but if a user is removed as an assignee, they remain on the People tab.