I wonder what compelled the authors to focus on Java first, given that it accounts for an ever smaller chunk of the code space and market share has been decreasing year on year for quite some time.
OpenRewrite also supports YAML based IaaC transformation, XML, Terraform HCL, etc. Typescript language binding is being built now.
We feel like to do this well, you really have to respect the idiosyncracies of each language and build for them.