The idea is that your WhatsApp notifications have more priority than those of any other application in your Android notification bar. It had already been rumored about this WhatsApp update; but now it has started to get to the beta version for Android. We talk specifically about the notifications that the app sends you.
The idea of this is that you can mark WhatsApp notifications as "high priority". This will be a configuration that you can change in Settings.
What's new in the green messenger is quite simple, in fact. Entering Settings of the app you can choose whether you want WhatsApp notifications to have high priority or not. This will cover each and every one of the notifications sent to you by the application; you will not be able to choose which ones and which ones (although it would be a good idea).
That is, if you decide that they are of high priority; these will appear above the others in your notification bar in Android regardless of the order in which they are coming. Until the beginning, WhatsApp will always be there. The configuration can be activated or deactivated to your liking.
In some cases they will even sound even if you have the silent mode activated. At the moment this is only available for beta users; but it will surely come to the public application very soon.