"I shouldn't have to change all these things for a temporary move."
Correct. As I stated, you would make those changes only if you did not plan to return to NY.
It sounds like NY still regards you as being domiciled in NY, and therefore subject to NY income tax. This reference gives the details on how NY determines residency for tax purposes (NYC's rules are the same):
https://www.tax.ny.gov/pit/file/pit_definitions.htm
**Answers are correct to the best of my ability but do not constitute tax or legal advice.
