My opinion:
Actually, it does for determining current annual income support for an immigrant because it is not CURRENT income. CURRENT income (and income which will be earned over the following year after immigrant arrival) is king. In other words, the income a sponsor/petitioner will have over the following 12 months after an immigrant enters the US is what supports that immigrant in the form of current annual income. That is CURRENT ANNUAL INCOME...not what was earned in previous years. Example: If I earned 100K last year, but I just lost my job.....My CURRENT annual income is now $0 if I am currently unemployed (with no other income coming).
On an I-864, there are 2 areas. CURRENT annual income (PART 6 item 7) is separate from the tax info the sponsor must provide in boxes PART 6 items 16.a-16.c. In other words, unless a person is self-employed, past tax reporting is not relevant to CURRENT income.
If you want to include saved funds from previous employment, it is not income...it would be liquid assets.
An unemployed sponsor should report current annual income as $0.00. Normally, CURRENT ANNUAL INCOME is supported by pay stubs, employment letters for W-2 employees, or profit/loss sheets in the case of self-employed sponsors.
Note: CURRENT ANNUAL INCOME can include Social Security, Retirement pensions, and even non-taxable income, etc.