I was wondering if it was possible to extract data from campaigns that have been deleted on Bing (data which bing claims will still be available for Bing Reports and on its API) ?
Does supermetrics get its data from the API ? or will that data be lost for my reports ?
Yes, Supermetrics uses Bing Ads API and the latest version of it. So basically if their documentation says that it is available to get data from deleted campaigns as well, then it should be possible with Supermetrics connectors.