According to the type definition, CleanupResult should have a property “deletedCacheRequests”. The PrecacheController returns a CleanupResult in the activate function, but instead of the “deletedCacheRequests” property you get “deletedURLs”

Type Definition CleanupResult:
https://github.com/GoogleChrome/workbox/blob/v7/packages/workbox-precaching/src/_types.ts#L17

Implementation of activate Function:
https://github.com/GoogleChrome/workbox/blob/v7/packages/workbox-precaching/src/PrecacheController.ts#L267