No, end-to-end encryption does not prevent Facebook from accessing WhatsApp chats
Just because WhatsApp is end to end encrypted doesn't mean it is the end all be all.
Metadata: Story Of How Whatsapp And Other Chat Apps Collect Data
WhatsApp is still collecting metadata and feeding it to Facebook.
"Whatsapp can collect data when, where, and with whom you communicate"
"Besides this, they collect information about your OS, browser information (think your search history on synced devices!), IP address, mobile network data, and phone number. And if they can’t obtain your phone number, they’ll obtain it when people message you, since WhatsApp has access to your friends’ activity data as well."