WhatsApp users on iOS already have available a new version, 2.21.71, with two important changes.
On the one hand, they have improved the display of multimedia content, offering larger previews of images and videos. On the other hand, WhatsApp only allowed administrators to control the messages that disappear, but now, with this update, all participants in a group can change the settings of messages that disappear by default.
Currently, iPhone users have very small previews of both photos and videos. This change will allow content to be viewed much more easily than before, which will avoid having to click on the image in many cases.
Regarding the control of disappearing messages. Administrators can still have control over the feature by changing the Edit Group Info setting, but participants will initially be able to decide whether they want it or not. This update is rolling out through the App Store and all users should be able to update soon. This appears to be a phased rollout, so you may not receive the update right away.
On that last feature, they are also testing the ability to bring the disappearing photos feature to the Android and iOS platforms. Once disappearing messages are enabled, text sent in an individual or group chat will disappear after seven days. This setting will not affect messages you previously sent or received in the chat before disappearing messages were enabled.