As is usual in Wikipedia, the more sources a claim has the more questionable it is.

Out of the six sources cited only two of them passes as reliable relatively recent scholarly sources, namely the Leonhard Theobald one in Beitrage zur Bayerischen Kirchengeschichte and the Alfred Altmann in the Jahresbericht of the Nuremberg Historical Society, and both of these sources actually dismisses that it ever happened according to the citations themselves.

Leonhard Theobald dismissal is cited as the following:

the Franconian Kreistag did not hold session between 1645 and 1664, and that there is no record of such a law in the extant archives of Nürnberg, Ansbach, or Bamberg, Theobald believing that the editors of the Fränkisches Archiv must have misunderstood a draft of some other legislation from 1650

Alfred Altmann describes the law as a "literary fantasy" and the 1790 periodical entitled Fränkisches Archiv, which seems to be the main source of this myth, as "merely a popular journal, not an edition of state documents".

Did someone edit the wikipedia article, because I can't find any reference to it now.