If a user is removed from a project (removed from the people list) and if a user is removed from a task assignment - does that remove their cost from the total labor costs for the project?
Did that user log time associated with an hourly rate? If so, then no - their hours are still included in the Finance > Actual Cost section, but you could manually delete any hours from the project, if needed.
Did that user log time associated with an hourly rate? If so, then no - their hours are still included in the Finance > Actual Cost section, but you could manually delete any hours from the project, if needed.