The roadmap is closed-source solutions as described here: https://discourse.nixos.org/t/introducing-flakehub/32044/3
Everything else we have is, and all of our improvements to Nix are, open source and permissively licensed. That includes Determinate Nix Installer and zero-to-nix, both of which are permissively licensed with the hope and intention of the upstream project adopting or integrating the material as they saw fit.