Apple Watch’s Walkie-Talkie app goes radio silent due to vulnerability

Apple disabled the app after somebody reported a bug - not exploited yet - that could allow an eavesdropper to listen in on another iPhone.
This is a companion discussion topic for the original entry at https://nakedsecurity.sophos.com/2019/07/12/apple-watchs-walkie-talkie-app-goes-radio-silent-due-to-vulnerability/