On Big Sur Beta 9 (9/30/20) the Terminal open command fails to launch script applications, both old and new. Nothing happens and the command returns without error. It doesn’t matter if Script Debugger or the Apple Script Editor is/was used to create the app or where the script app exists, even in the Applications directory. Example: ‘open -a TestScriptApp’. I’ve reported this via Apple’s Feedback Assistant app.
Applescript apps cannot access command line parameters, so I have lots of scripts use the open command to indirectly pass them via environment variables, which is quite handy. My script ecosystem is quite broken until this gets fixed.