I’ll preface this by saying, I know this board isn’t an issue list, and I don’t intend to treat it like one.
So with that out of the “check out this bizarre issue” 
Nix 2.7.0 issue with nix-commands for multiple output path derivations. · Issue #168354 · NixOS/nixpkgs · GitHub
Basically fresh installs 2.7.0 on Debian 11, or nixUnstable on NixOS both fail to install multiple outputs for nix profile install.
If you explicitly name every output though they work.
Additionally if you try nix shell, it will give you out regardless of whether references to other outputs can be found. Probably not going to be pretty if you need anything from lib.
The issue effects other packages, and all of them had multiple outputs when I checked.