Just an opinion: I wish the plural "you" form allowed the response "you all" so as to help me distinguish it from the singular "you" form.
Sometimes it does. Sometimes it doesn't. And sometimes it demands it and doesn't allow just "you" ...
You (pl) = you all. The answer should allow 'you all' when you (pl) is intended.
12 March 2020, still not accepting plural.
Also, maybe I'm just a little bit redneck, but I would appreciate "y'all" as an appropriate answer as well.
"y'all" is a real English word