The organisation exists, auxolotl · GitHub. To join make a post here GitHub Organization Membership.
Here is a good place to start reading in prep for the hard fork. SIG Repos: How should they work?. In the mean time we are following a soft fork workflow where you contribute to GitHub - auxolotl/nixpkgs: Nix Packages collection & NixOS like you would for nixos/nixpkgs.
Do you mind expanding on this?