Last tested: Sep 18, 2019
No, the default values for the filters on the Dashboard set at the time the schedule is created are the values that will be applied to the schedule (until they are changed manually in the schedule). Changing the default values for the filters on the Dashboard after the schedule is created will not update filters for existing schedules.
To apply the new default values to a schedule, you can either create a new schedule with the same settings (save for the filters) as the old one, or manually update the filter values on the older schedule.
You can add your vote to allowing a schedule to automatically inherit a saved Look default filter values here.