Microsoft today released a new Skype Insider Preview build for Android, iPhone, iPad, Web, Mac, Linux, Linux Snap, Windows 10 PC & Android 4+. This new v188.8.131.52 build allows you to disable incoming video. This feature will be useful in the scenarios where you want to save data and improve your audio call quality. Download the updated app from respective stores.
Note: The Skype Windows 10 store app was not updated yet due to crash issue, but Microsoft is working to fix it soon.