Temporarily … In the Analytics Overview there is a small icon at the top right of the screen by the CUSTOMIZE button. It looks like a megaphone. Click on that and it will take you back to the old reporting. Apparently, going forward everyone will be moved to the new report system that will no longer recognize deleted products, which imo makes the reports useless.
So if you don’t want to lose the data, you can’t clean up your old skus 