WhatsApp is experimenting on a ‘Read Later’ feature, which is simply a reconfigure of Whatsapp Archived Chats. As the name indicates, ‘Read Later’ will keep all chats attached to this list on mute, and new message alerts will not be provided for these chats to avoid regular disruptions. Users can basically place unwanted chats from groups and individuals in this upcoming feature.
In the Whatsapp Android beta, changes to this feature were noted. There are instances of the Read Later functionality being in the process for the latest WhatsApp for Android beta v188.8.131.52. WhatsApp for iOS beta v184.108.40.206 has this function listed in November. Even if you install the updated version, you wont be able to see it it.
You can get an introductory message if you click on it. This reads “to prevent interruptions, conversations with new messages will remain here and you won’t get any alerts”. This is intended to minimise clutter and enable users to organize their chats a little better.
As of now, we do not exactly know when this feature will completely roll out and replace with Whatsapp archived chat. Depending on the success or nature of this new feature, these items will take a while.