Vi's taunt audio is playing on her Neon Strike skin.

On Vi's classic, Officer, and Debonair skins, when you taunt she spits and says one of the following lines. "I've got five reasons for you to shut up." "If I want your opinion, I'll beat it out of you." "I like you as far as I can throw you... not even."

These normally don't play in her Neon Strike skin. Instead it toggles how she wears her sunglasses. However, recently it the audio for the taunt has been playing on this skin. That included the sound for her spitting.

I do believe this to be a bug as it had never been a part of the skin up until now. Easy tested. Just start a game as Neon Strike Vi in a custom and play your taunt.