WhatsApp implemented the feature some time ago so that only group admins can send messages, and from now on this new feature is being activated on all their platforms, although it seems that in Android and Windows Phone activation will be slower.
This way, if you are an admin of a group, you can make it so that only you can send messages, thus silencing other participants, who can only send messages to the admin, but who will not appear for the rest of the participants. You can re-enable all participants to send messages at any time.
Enabling Send Messages Only Admins
To activate this new function from the group chat, go to “Settings (3 dots vertical at the top right) > Group info > Group settings > Send messages“. From here you can select whether only administrators can send messages or all participants.
We already saw this feature some time ago in GBWhatsApp Plus, but it was not recommended to use it, from today you can start testing it without risk. WhatsApp for Android is being activated from beta version 2.18.201 and stable version 2.18.191, but slowly. In WhatsApp for iPhone activated as of version 2.18.70.
Via | DownloadAppsMobile