Rosetta 2 decodes Intel instructions and produces equivalent ARM instructions to be executed by the processor. Rosetta 1 decodes sequences of PowerPC instructions and generates an equivalent sequence of Intel instructions, which are then executed by the Intel processor. In addition, the question in your thread title suggests that you misunderstand what Rosetta does. It does not provide a way to run an entire Intel operating system in a virtual machine, and cannot be used to assist virtual machine software to run Intel code inside a virtual machine. Rosetta 2 has nothing to do with this: it provides code translation to run Intel processes on an Apple Silicon Mac under the host macOS. This would be similar in concept to products like Virtual PC (from Connectix, later bought by Microsoft) which emulated an Intel PC down to the processor instructions, and allowed running DOS or Windows on a PowerPC Mac.

The best way this could be achieved would be if someone released a product which went beyond virtualisation and also emulated an Intel processor. Therefore with the initial release of VMware Fusion for Apple Silicon Macs, there will not be any way to run old PowerPC-only applications like Eudora and Palm Desktop. Those will not work under the expected initial release of VMware Fusion for Apple Silicon Macs. To run PowerPC applications under Rosetta, you would need to be able to run the Intel versions of Mac OS X 10.6 Snow Leopard Server or Mac OS X 10.5 Leopard Server in a VM. For example, this would allow running ARM-based Linux variants, or macOS Big Sur in virtualisation on an Apple Silicon Mac. This will not extend to running older macOS versions (macOS Catalina 10.15 or earlier), since they are Intel operating systems. When VMware Fusion is released for Apple Silicon Macs, the expectation is that it will initially allow virtualisation of ARM-based operating systems.

The short answer: no to scenario 1, and scenario 2 is not applicable or relevant.

Emulator for mac os x snow leopard