You're dodging the allegation. It's not that it's not public information or that it must dictate the vote. It's that there's no reason for the poll worker to ask or know what you party registration is prior to sending to you machine A or machine B. At best it's a non-issue, at worst it's an opportunity to steer voters to a broken machine.

Any comparison of total turnout v.s. historic turnout based upon political party could be done after the fact anyway.