I think instead of echo env we should do the more general

  string replace -r '^.*/conda-' '' "$_CONDA_ROOT"/bin/conda-*

or maybe better

  for f in "$_CONDA_ROOT"/bin/conda-*
    if test -x "$f" -a ! -d "$f"
      string replace -r '^.*/conda-' '' "$f"
    end
  end

That way we would also pick up other commands, e.g., from conda-build.
NOTE: I have next to no fish experience, so I don't know certainly if the code snippet above is fine or not.

Good idea! I think the first is fine. We don't have conda directories AFAIK, and we might discover other things to exclude later anyway.

I was more thinking about the test -x part, i.e., to only pick up executables. The -d part is only to a necessary addition.
If one would do something like writing a (of course non-executable) conda-build.log file to bin or another stupidity, then we can easily exclude that with the second code snippet.
(BTW, conda itself doesn't do that executable test yet and thus will ungracefully exit if you were to run it with such conda conda-build.log -- I'll submit a PR for this.)

Looks strange to me to have non-executable files in bin but ok, done. :)

Definitely agree to that. But who knows what people might do 😉 -- we can always remove that check later on.
One case where we have non-executables would be on Windows where (due to no shebang support) a single conda script is replaced by conda.exe and conda-script.py (with the former essentially running python conda-script.py).
But well, to satisfy the "immensely large" Windows+fish+conda user base, we'd have to glob for conda-*(.exe)? or something 😆

Hahaha this immensely large user base will certainly submit a PR if there's an issue 😆