modifying the original file on disc does not in any way inform the authoring tools that a change has taken place since the time you either imported the file or the last time any data derived from the file ( such as the waveform display or conversion properties to which i suspect you refer ) was gathered.
reconverting the file ( shift+c ) should address any inaccuracies in any displayed data - building somebanks already takes into account any changes made and so is not affected.
hopefully it is clear that this is a resonable compromise in the general case - e.g. a great many things could change that file, that wwise wouldn't know about, should you wish.
i do however take your point that, considering the operation to modify the file is launched from within wwise that, once editing is is concluded that wwise could update any data derived from the file either through waiting for the editor, launch as a child process, to terminate or through the use of file/directory change notifications https://docs.microsoft.com/en-us/windows/win32/fileio/obtaining-directory-change-notifications
in much the same way as i'm suggesting you do manually.