I think an important distinction to make here is that the new 3CX Desktop App does not replace the 3CX Windows Client. What your screen shot refers to is the Windows Client, the settings are still there. You can still use it for all of your needs if you'd like, it has not been deprecated.
The new Desktop App has a Panel tab that will give you an overview of queues and all calls:
You can select what you'd like to see from the All tab, and even pop it out as a separate window using the pop out icon marked in blue.
Can you show me where it's telling you that the 3CX App requires 3CX Phone System Version 16? I'm using the Windows Client now with extensions from a V18 PBX.