Everyone needs tax return transcripts for last 3-5 years as it relates to your LPR status varification plus ( as I interprete it) they want to make sure you do not have tax liability outstanding. Thsi requirement has nothing to do whether you file as a spouse of a US citizen or on your 5 year GC period.
Additionaly, if you are filing N 400 as spouse of US citizen, they want to see if you are filing joint tax return or not, you have joint bank account or not, living togethr or not etc to check if the marriage is still on or broken up by the time you have appeared for the interview.
please read discussion under this forum for more on tax return.