I'm curious what Parallels going to do. Running Windows and Linux applications with almost native integration into OSX ecosystem worth a lot, especially with all benefits of hardware virtualization. In theory PC could be virtualized on ARM, however software virtualization only. Going to watch the process. In general, Windows and Linux support ARM as well, not sure if hardware virtualization for ARM exist though
Also, the move to Catalina helps to check how fast app developers and users switch to new hardware.