It at least used to be true. In the May 2007 REG, page 244:
"If John’s special ability is negated, shuffle the draw pile that was looked through."
I doubt this is the case anymore - this is over 5 years old - but it was my favorite obscure ruling at the time. And yes, I'm allowed to have favorite obscure rulings, just like I'm allowed to have favorite obscure cards (Discord), favorite obscure They Might Be Giants songs (I Blame You), and favorite obscure people on my family tree (my great-uncle Konstanty Mierzejewski was a bootlegger during the Great Depression).