Per @Michael_Kirschner2 request I started a new topic to track the issues with installing Dynamo 2.0.0 after 1.3.2 is installed and breaking Python Scripts in either version of Dynamo.
The original post is here, Dynamo and IronPython - incompatibilities with other applications
As additional test, I tried this on my virtual machine that I already had set up and tested in Revit 2018.2 and everything worked fine.
Additional here are some notes from my previous post tests. That machine did have Revit 2019 installed (the virtual machine did not), which installed Dynamo 1.3.3. Therefore after installing Revit 2019, I uninstalled Dynamo 1.3.3 and installed Dynamo 1.3.2 and then installed Dynamo 2.0.0. I also had Dynamo Studio 1.5 installed and found that in order to install Dynamo 1.3.2 after uninstalling 1.3.3 I had to uninstall Dynamo Studio. Then they dynamo installer for 1.3.2 worked fine.