Why did city utility work require me to modify my faucet aerator?
The most likely scenario is that the work on the system disturbed sediment/debris that migrated to your home water piping, plugging up your faucet aerators. Rather than the "quarter turn" you describe (which would accomplish nothing) it is probable that the aerators were removed, flushed, and reinstalled to restore flow.

You should remain diligent, it is not uncommon for additional debris to continue to cause issues. Not just aerators but toilet fill valves as well.