[ComputerGuru]

Not autoload, no. You can have as many functions as you want in a single .fish file, but it'll only be lazily autoloaded if it has the same name as the command you are trying to execute. It's how we avoid doing the I/O of scanning all fish directories and parsing their contents at startup.

[PittleyDunkin]

...and you can still explicitly source the files if you want to load the functions elsewhere.