Where's the provision in the Constitution to decertify an election? Sheesh, I thought liberals were dumb...
I'm sure you know just as well as the rest of us that the Tenth Amendment reserves to the States, and the people, all powers not specifically delegated to the Federal Government. If the legislature of AZ decides that it no longer has confidence in the result it previously certified and sent to the joint session, as the sole determiner of election procedure in AZ it has all authority to say so by de-certifying.
Even if every state that certified D EVs chose to de-certify, Biden would remain at the Resolute desk; one can reasonably argue that de-certifying would be merely symbolic, with no real impact. AZ, PA, GA, and other states simply screwed up by certifying results that came from procedures that are not trustworthy. Although moot in terms of immediate impact, de-certifying would say clearly that existing electoral procedures are unacceptable. If the AZ legislature chose to de-certify, they would really have no choice but to reform their election laws.
I take no position on whether or not a proposed de-cert would stand a chance in the AZ legislature. In a sense de-cert would be an admission of failure by the state legislature, an admission it had allowed untrustworthy procedures to remain in effect. For that reason alone the proposal might be a non-starter.