WhatsApp for Windows phone by default shows all the received messages in notification area. While this helps in knowing the latest updates, lot of messages can quickly clutter the notification area.
This can be changed so that no WhatsApp messages are displayed in the notification area.
Here is how:
Open WhatsApp and tap the dots icon.
Then choose settings.
Select chat settings and turn off the option of preview messages in notification.
From now on, no WhatsApp messages will be visible in notification area.