The Default_MYOBA_Warehouse__c value for a state should be based on an available Warehouse__c picklist choice for that state on the Opportunity object.

When set, this field will determine what the fallback Warehouse__c value will be for any Services created using the new Restocker App where the assigned to user does not have their own Warehouse__c value. If neither the assigned user or the default warehouse is set, the new service will be created with a blank warehouse value.

This field may interact with other automation for Opportunities and should not be set specifically for restocking without consideration for secondary impacts.