Wouldn't this violate the federal Constitution? > No State shall enter into any Treaty, Alliance, or Confederation; grant Letters of Marque and Reprisal; coin Money ; emit Bills of Credit; make any Thing but gold and silver Coin a Tender in Payment of Debts ; pass any Bill of Attainder, ex post facto Law, or Law impairing the Obligation of Contracts, or grant any Title of Nobility. -Article I, Section 10, Clause 1
I am totally against all things Bitcoin, however, it's not coined exclusive in the us and the constitution is not immutable, else it would be a very bad document that can't get with the times. Anything in the constitution is not canonical forever.
It is, however, canonical until amended or SCOTUS interprets it away.
Constitutionally, it appears quite clear Arizona can't do this currently, and the law as a result would almost certainly be immediately stayed and struck down if passed.