Does updating the Task Work Type affect all Expenditure Items or is there a scheduled process?

Hi, we're looking at potentially using Work Types to control the billing of expenditure items at a task level. Is there a scheduled process to update the work type for all expenditures attributed to a task at the point the task itself is updated to a billable work type? Or do we have to update each one manually in Manage Expenditures.

I've seen the 'Update Work Type' process but it's not clear to me what this is representing.