A lot of features have been rolling out to WhatsApp in the past weeks; more are still expected to roll out. Well these features are currently rolling out to beta users which we talked about some weeks ago.
New UI for Voice Call
WhatsApp is also revamping the interface when you place a group voice call, bringing voice waveforms for all participants during the call. Aside of this, another feature, the ability to use a wallpaper when placing a voice call is also rolling out.
This update is rolling out in batches, and should be fully rolled out in the next few weeks.
Dark Theme for UWP:
WhatsApp has recently introduced new updates for Universal Windows Platform which includes different improvements for the user interface: minor animations, improved design for chat bubbles, and more. Today, WhatsApp is finally implementing the dark theme.
If you use the dark theme on Windows, WhatsApp will automatically set the theme to dark. Alternatively, you can choose the theme right within WhatsApp Settings > General. When you want to use a different theme, you have to restart WhatsApp to apply the changes.