It was documented for zsh but not fish (2 lines above).
While looking for how to do the same in fish, I couldn't find how to do
*exactly the same*, but turns out there's a neat way to do both the
aliasing and autocompletion mapping at the same time.
See https://fishshell.com/docs/current/cmds/function.html :
> `-w WRAPPED_COMMAND` or `--wraps=WRAPPED_COMMAND` causes the function
> to inherit completions from the given wrapped command. See the
> documentation for [complete](https://fishshell.com/docs/current/cmds/complete.html#cmd-complete)
> for more information.
c40bd7ce82