Just got a response from whatsapp support. AS follows
We appreciate your feedback about WhatsApp compatibility with Windows 10 Mobile and apologize for the inconvenience.
We are currently not supporting WhatsApp on Windows 10 Mobile. Please understand that even though WhatsApp may work on your device, we are not able to address any issues you may encounter.
Our developers are working on providing you with a compatible version.
Thank you for your patience and support for WhatsApp.