GOT IT working (i think)

it was far far better to alias the vlc to a short command first (syntax creep was occurring) and without that alias, i got a detailed zsh error & went on a goose chase (honk)

literally, it's just:
➜ ~ youtube-dl $(pbpaste) -o - | vlc -
(like the doc says)
pobody's nerfect ¯\_(ツ)_/¯

and if you want it to automatically go, gotta use this because it's treated like a playlist, not a file

youtube-dl $(pbpaste) -o - | vlc - --playlist-autostart