Okee dokee, this might be totally off but... this is what I found. "What You Will", an old phrase from (at least) the 1500-1600 (Elizabethan period)... "What you will" means 'whatever you want to call it'(like a dismissive phrase). So..... it is plausible (and I chose my words wisely) that it could have derived from that phrase. Weeewwwhhh! Well I gave it shot! Even if I'm wrong no know for a fact it didn't come from "Friends", the saying was around in the 60's (so my mother tells me).
Annnnnnnnnndddd I'm done...