Your lady friend's take is the same as I was taught for the decennial census which I did in both 2010 and 2020.

I think who the OP is probably dealing with is a permanent census bureau employee conducting a survey other than the decennial (the actual Census required by the US Constitution).

All 2020 field operations have been done since late 2020.

All the other surveys the census bureau conducts are absolutely voluntary to the best of my knowledge.

Edit: I just checked on the census bureau website - they are currently doing 130 surveys, none of which are the actual decennial census.