I have searched and found a Salesforce WhatsApp group and a Salesforce Facebook group.

I have also found a company SaaSnic Technologies who says if you provide your mobile number then they will join you in his WhatsApp group.

SaaSnic Technologies is a reputed Salesforce Development and Consulting company which offer his services for the different domain. Including Information Technology, Automobile, and Retail, Aeronautical, E-Commerce, Legal Services, Professional, Investment and finance and so on.

The information I have filtered I tell you, If you want to join SaaSnic Technologies then join his Whatsapp group on your own risk

Check this article on "Whatsapp Salesforce Integration". You can send and receive messages from Salesforce to Whatsapp using Yowsup library, which is a free open source python library. Hope this gives some direction