One specific thing I think FP distributed-system frameworks could bring is instantaneous, deterministic testing.
e.g. I have N microservices, they communicate via IO (which means slow/brittle tests) but the framework abstracts over that, so I can run the whole system test suite under a second, because all IO (messaging, DB, concurrency) can be replaced with an in-memory implementation.
Interestingly, one could also inject faults to those IO mocks, and test how the system respond to that.
I believe FP is a prerequisite for meeting those goals, because otherwise having impure IO all over the place is hard (if not impossible) to mock out.
as I can see Metaparticle is a tool specifically built for Kubernetes and uses its API underhood. Parapet can be extended to support Kubernetes ecosystem how it was done for ZMQ. Parapet can be integrated with Metaparticle, so that you can run the same distributed algorithms written in Patapet in a Kubernetes cluster.