I can only tell you of my experience. I have an LG G2 Android. It came with VuTalk, an app that let 2 VuTalk LG capable phones send screenshots and edited photos, memos, ect... and share the screen while on a voice call. The app was discontinued by LG, have have my suspicions as to why (later) and the app would no longer open, but the icon and app remained. LG later released a small update within a Verizon update (very incremental and not related to the OS) that installed an app that uninstalled VuTalk and then uninstalled the uninstaller. This got rid of the app and its icon.
My thought is that since VoLTE Advanced Calling 1.0 came out around the same time the app was discontinued seemed to me that VuTalk, having similar capabilities as AC1.0, in that simultaneous video calling and voice service was a conflict of interest. Obviously that has no bearing on your issue, but mine was similar in the discontinued app aspect. Long story short: the app would be removed with a future update. I also was not given an alternative app to use in place of VuTalk.
