That's just a mod of the Google YouTube app, if memory serves. It probably still relies on normal Play Services, and is likely nonfree anyway.
Edit: Vanced relies on MicroG for logging in, and requires it to be installed along Vanced even on phones that have the "real" Google Play services.
Edit 2: I took "Chinese Android roms" as an example for Google-less roms. Of course, Vanced can't help in bypassing the Chinese firewall to contact Google servers.