A quick one to those with DTKs.
Does Rosetta v2 support 32bit intel apps, or does it only support 64bit apps?
64-bit only. As others have stated, you're not going to have Catalina drop support for 32-bit Intel binaries only to have Rosetta 2 re-introduce said support. I'm pretty sure this was all a part of the plan and that, as a result, more things will work in Rosetta 2 than did in its PowerPC-to-Intel predecessor.
They really need to start publishing a list of major developers who are offering dual binary support along with a list of applications working within their Rosetta V2 platform.
Considering how closely timed this was with Apple dropping support for 32-bit Intel applications, it's very likely that most 64-bit Intel applications (obviously excluding Intel native versions of Parallels, Fusion, and VirtualBox) will just work and that such a list won't be necessary.