The writing was on the wall. In February 2014, Facebook acquired WhatsApp in a huge deal. A long wait followed to see when and how Facebook will begin to monetise the huge amount of user data that it acquired along with WhatsApp.
Following that, these updates were announced:
(1) WhatsApp data will be used by Facebook to send advertisements (source: theverge.com)
(2) WhatsApp will begin to send advertisements to users

Implications for Privacy

1. All the private messages, pictures, videos (that users send on WhatsApp) are now likely analysed for advertising trends.
2. It follows that all these information, including the embarrassing or undesirable, is archived somewhere (even though there is supposedly end-to-end encryption).
3. The primary criteria for mining information is mileage for advertising.

Implications for Cyber Wellness

(1) Users need to be continually vigilant on what we share on any social media platform - embarrassing information will not disappear or be deleted

• Young children are especially vulnerable because most sites they use collect information for advertising.
• What may not embarrass or concern users now may show up to be a concern later

(2) Take precautions and make privacy changes

 
(3) Back to Step 1 - continue to be vigilant because it is unlikely that this will be the last attempt to monetise user data

This comment is an opinion and not yet a fact - like we first talked about the possibility of data sharing with Facebook 2.5 years ago. However, current business models of most social media platforms (Snapchat, Google, Facebook etc) point to a likely and continual attempt to maximise monetisation & alter users' notion & expectations of privacy.