Per CA Publication 1031, CA's rule is: "Any individual who is a resident of California continues to be a resident when absent from the state for a temporary or transitory purpose."
Page 6, https://www.ftb.ca.gov/forms/2020/2020-1031-publication.pdf
The taxpayer "relocated" to AZ in March of 2020, abandoning his home in CA. So the question is whether that move was "for a temporary or transient purpose", or did the taxpayer intend to make AZ his new home? Note that the taxpayer said that he "may" have to move back to CA, not that it was his intent to do so.
If the move to AZ is intended to be permanent, the taxpayer files two part-year resident returns.
Additionally, earnings from remote work actually carried out in AZ are AZ-source income per AZ Statute 43-104 (9), and are taxable by AZ.
https://law.justia.com/codes/arizona/2018/title-43/section-43-104/
**Answers are correct to the best of my ability but do not constitute tax or legal advice.
