All the listed languages are compiled and statically typed. Python is neither. Neither is JavaScript, another popular programming language which is also not listed.
I don't see how the static typing of the bound languages enters into it. Python has type hints which can be enforced by some compilers, if you are so committed to type safety in your config scripts. If you have Pkl output YAML or XML then where is your type safety?
Since "popular" does mean that very many people are using it, I think it would be wise to try to serve the Python community.
Since "popular" does mean that very many people are using it, I think it would be wise to try to serve the Python community.