I'm wondering why is this news can be seen only on crypto related sites apart from The Daily Express which regarded as a tabloid and thus seen by many as not a reliable source of information. This is a very good news for Bitcoiners if it is true, but I've managed to find only the information below on cointelegraph, which looks more or less reliable:
The bill has now been sent to Arizona’s House of Representatives.
If the bill is adopted, Arizona would become the first state in the U.S. to accept cryptocurrency tax payments by the year of 2020
So, it looks like it's not final yet according to the quoted text.
I think that if Arizona will be procrastinating the decision, it will end up being among many others who will be accepting crypto tax payments by 2020 and thus it may lose the pioneer status. Btw the municipality of Chiasso in Switzerland has already allowed its residents to pay taxes in Bitcoin since January 2018.