iCloud Keychain passwords gone after erasing settings

Hello fellow Apple Community users.

fter erasing settings from my iPhone 6 with iOS 8.0.2 to solve this problem: Today summary in iOS 8 not working correctly

all my Wifi passwords from iCloud Keychain were gone on all my devices.

Next to my iPhone 6 I own an iPad mini retina (iOS 8.0.2), a MacBook Pro Retina (10.9.5) and a Mac mini (10.9.5). On all these devices all my Wifi passwords were gone.

Today I read about problems concerning deleted files from iCloud drive after erasing an iOS device. Does anyone know whether this also affects iCloud Keychain? Did anyone have a similar experience?

Regards

Fennek