If you have connected QuickBooks Online to your Dryrun Forecasts and Scenarios, selecting Refresh will bring in new data from the account, and your Dryrun scenario will be updated.
That said, if you delete an item in QuickBooks Online, it will not be reflected in Dryrun, and you will have to manually delete it.
We have requested that QuickBooks Online supply this data to integration partners and hope to add this functionality in the future.