Agree for iOS, i didn't know the list of installed packages was only known to Apple. On Android, it seems to be a new restriction that is being deployed in A11 (search for discussions on Android developers inquiring about the new "QUERY_ALL_PACKAGES" permission that some are struggling with already.
For the exaggeration, I would happily answer but I would need to know on which access you felt I exaggerated (except the fact I did not know Apple kept this list only to itself and friends). The data categories I mentioned are quite straightforward and not specifically obtained by WhatsApp only.