Glad you got a response from Whatsapp.....I didnt!!!!!
Their initial automated email says to update to latest version via their site.
This I did (2.11.73) & I havent had any issues yet (although I think I may have hit the remind me in 30 days box in the security warning!!!)
I now notice there is a new up date (2.11.79) So I will try that & keep my fingers crossed!